EP4128324A1 - Removable structure used for the transfer or manipulation of layers, and method for transfer of a layer using said removable structure - Google Patents

Removable structure used for the transfer or manipulation of layers, and method for transfer of a layer using said removable structure

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Publication number
EP4128324A1
EP4128324A1 EP21719192.3A EP21719192A EP4128324A1 EP 4128324 A1 EP4128324 A1 EP 4128324A1 EP 21719192 A EP21719192 A EP 21719192A EP 4128324 A1 EP4128324 A1 EP 4128324A1
Authority
EP
European Patent Office
Prior art keywords
interface
removable structure
assembly
substrate
useful layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21719192.3A
Other languages
German (de)
French (fr)
Inventor
François-Xavier DARRAS
Vincent Larrey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Soitec SA
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
Soitec SA
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Commissariat a lEnergie Atomique CEA, Soitec SA, Commissariat a lEnergie Atomique et aux Energies Alternatives CEA filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP4128324A1 publication Critical patent/EP4128324A1/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • H01L21/185—Joining of semiconductor bodies for junction formation
    • H01L21/187—Joining of semiconductor bodies for junction formation by direct bonding
    • 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
    • H01L21/02002—Preparing wafers
    • 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
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
    • 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
    • H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
    • H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
    • H01L21/7806—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices involving the separation of the active layers from a substrate

Definitions

  • the present invention relates to the field of thin film transfer for microelectronic, optical, microsystems, etc. applications. It relates in particular to a removable structure that can be used for the transfer or handling of thin layers.
  • Some transfer methods consist of assembling the thin film (placed on the initial substrate) and the target substrate, then mechanically and / or chemically removing the initial substrate, thereby transferring the layer to the target substrate.
  • the main drawbacks of this approach are the costs associated with the loss of the initial substrate and the restrictive mechanical and chemical treatments liable to degrade the quality of the thin film during the transfer.
  • a difficulty associated with these approaches is that the detachment can sometimes be done at the level of interfaces or layers other than the weakened one because the mechanical stress and / or the chemical attack can hardly be localized precisely at the level of said weakened layer or interface. .
  • the variability of the geometry of the edges of the substrates, the method of applying the mechanical stress or the chemical etching solution for the dismantling can induce the start of the separation at an interface other than the weakened one, even if this other interface has a mechanical strength greater than the strength of the weakened interface.
  • these arrangements do not always make it possible to prevent the initiation of separation at a non-target interface.
  • Document FR2995446 addresses removable structures comprising at least two interfaces, including the weakened one at which separation is expected. It offers solutions for redirecting the separation front towards the weakened interface when the latter starts at the level of the other interface.
  • the present invention relates to an alternative solution helping to localize the detachment at the weakened interface of a removable structure.
  • An object of the invention is a removable structure comprising at least two interfaces, one of which is the weakened interface or the privileged detachment interface. Said removable structure is used for the transfer or handling of layers.
  • the present invention relates to a removable structure for transferring or handling layers, comprising:
  • a donor substrate comprising a useful layer to be transferred placed on an initial substrate
  • the privileged detachment interface being located between said useful layer and the initial substrate
  • the assembly interface being located between said useful layer and the recipient substrate .
  • the removable structure is remarkable in that the assembly interface has an assembly interruption zone comprising at least one cavity present in the receiving substrate or in the useful layer, in the latter case, the depth of the cavity being strictly less than the thickness of the useful layer.
  • the assembly interruption zone is located in a peripheral region of the dismountable structure, it makes it possible to modify a stress field at the head of the front of a separation wave when the latter is initiated in the assembly interface to the transfer or manipulation of the useful layer.
  • the modification of the stress field by the -at least one- cavity of the assembly interruption zone allows the deviation of the separation wave, from the assembly interface to the privileged detachment interface, thus allowing a transfer of the useful layer on the receiving substrate.
  • the assembly interruption zone extends over a length, along the perimeter of the removable structure, less than or equal to 20mm;
  • the assembly interruption zone is located less than 10mm from the edges of the dismantling structure
  • the (at least one) cavity has lateral dimensions of between a few microns and a few millimeters, preferably between 20 microns and 1mm; • the (at least one) cavity has a depth of between 0.5 microns and several tens of microns, typically 50 microns;
  • the (at least one) cavity has, in a plane parallel to the assembly interface, a square, rectangular, triangular, trapezoidal or rounded periphery;
  • At least one rectilinear segment of the perimeter of the (at least one) cavity is parallel to a dismantling edge of the removable structure or to the tangent to a dismantling edge of the removable structure;
  • a rectilinear segment of the perimeter of the (at least one) cavity which has the largest lateral dimension, is parallel to a dismantling edge of the removable structure or to a tangent to a dismantling edge of the dismantled structure;
  • the assembly interruption zone comprises a plurality of cavities spaced apart by a distance of between 1 micron and 1mm, typically between a few microns and a few hundred microns;
  • the cavities are aligned along a straight line or along a curved line, the convexity of which is oriented towards the center of the removable structure;
  • the assembly interruption zone is positioned less than 8mm from the edges of the removable structure, or even less than 3mm;
  • the useful layer has a thickness between a few hundred nanometers and several hundred microns, typically between 200 nm and 200 microns;
  • the privileged detachment interface presents a first interfacial energy
  • the assembly interface presents a second interfacial energy
  • the difference in interfacial energy between the privileged detachment interface and the assembly interface is greater than or equal to 1000 mJ / m 2 ;
  • the preferred detachment interface is a bonding interface by molecular adhesion having a first bonding energy
  • the assembly interface is a bonding interface by molecular adhesion having a second bonding energy, the first bonding energy being less than the second bonding energy
  • the difference in bonding energy between the privileged detachment interface and the assembly interface is at least of the order of 1000 mJ / m 2 .
  • the invention also relates to a method of transferring a useful layer from a donor substrate to a recipient substrate, comprising the following steps: a) providing a removable structure as above, b) applying d 'a mechanical stress at the level of a dismantling edge of the removable structure, said dismantling edge being located closest to the assembly interruption zone and the mechanical stress being able to initiate a separation wave at the assembly interface or at the privileged detachment interface, c) if the initiation of the separation wave occurs at the assembly interface, the deviation of the separation wave in the detachment interface privileged when the separation wave passes through the assembly interruption zone, d) the propagation of the separation wave at the privileged detachment interface, to result in the total separation of the dismountable structure.
  • step a) comprises: o the supply of the donor substrate comprising the useful layer placed on the initial substrate, the privileged detachment interface being located between said useful layer and said initial substrate, o the supply of a recipient substrate, the formation of at least one cavity opening at the level of a face to be assembled of the recipient substrate or at the level of a face to be assembled of the useful layer, in a peripheral region of the recipient substrate or of the useful layer, o l assembly of the useful layer and of the receiving substrate at the level of their respective faces to be assembled.
  • Figures la and lb show respectively a sectional view and a plan view of a removable structure according to the invention; in the plan view, the cavities are made visible for a better understanding of their distribution and location, whereas they should be masked because they are arranged between the useful layer and the receiving substrate.
  • FIGS. 2a, 2b and 2c respectively show a sectional view and two views in the plan, of a removable structure according to the invention; on the views in the plan, the cavities are made visible for a better understanding of their distribution and location, whereas they should be masked because they are placed between the useful layer and the receiving substrate.
  • FIG. 4a shows a plan view of a structure that can be dismantled during the step of applying a mechanical stress, step of the transfer method according to the invention
  • FIG. 4b shows a photo, zoomed around the assembly interruption zone, of the transfer of a useful layer onto a receiving substrate at the end of the transfer process according to the present invention.
  • the figures are schematic representations which, for the sake of readability, are not to scale. Specifically, the thicknesses of the layers along the z axis are not to scale with respect to the lateral dimensions along the x and y axes.
  • the invention relates to a removable structure 100 comprising at least two interfaces, an assembly interface 30 and a privileged detachment interface 1.
  • the two interfaces extend in planes parallel to the plane (x, y). ⁇
  • removable structure is understood to mean a structure 100 intended to be subjected to a mechanical stress in order to initiate a separation, desired at the level of the privileged detachment interface 1; due to the presence of the second interface (assembly interface 30), there is competition for propagation of the separation wave between the two interfaces 1.30.
  • the removable structure 100 comprises a donor substrate 10 including a useful layer 3 to be transferred placed on an initial substrate 2; the privileged detachment interface 1 is located between the useful layer 3 and the initial substrate 2.
  • the useful layer 3 can be formed from a semiconductor material, such as silicon, silicon carbide, germanium, a III-V compound, ..., and / or an insulating material , in particular piezoelectric, such as lithium tantalate or lithium niobate.
  • a semiconductor material such as silicon, silicon carbide, germanium, a III-V compound, ..., and / or an insulating material , in particular piezoelectric, such as lithium tantalate or lithium niobate.
  • piezoelectric such as lithium tantalate or lithium niobate.
  • the useful layer 3 can also comprise a plurality of films of different materials, and / or functional structures (for example cavities) in particular on its face vis-à-vis the receiving substrate 30, and / or all or part of microelectronic components.
  • the adhesion between the different films or stacks of components is of course expected higher than the holding of the privileged detachment interface 1, the characteristics of which will be detailed below. In general, the characteristics of the useful layer 3 depend on the targeted application and the desired functionalities.
  • the useful layer 3 has a thickness between a few hundred nanometers and a few hundred microns, for example between 200 nm and 200 microns, or preferably between 1 micron and 50 microns.
  • the initial substrate 2 is advantageously formed by a low-cost material, providing good mechanical support for the handling of the useful layer 3.
  • silicon is generally the material of choice because of its material. compatibility with any microelectronic manufacturing line.
  • the initial substrate 2 can be in the form of a wafer with a diameter of 100mm to 450mm and a thickness of between 250 and 850 microns for example.
  • the initial substrate 2 can alternatively be in other shapes (square for example).
  • the removable structure 100 further comprises a recipient substrate 20, assembled on the donor substrate 10: the assembly interface 30 is located between the recipient substrate 20 and the useful layer 3.
  • the receiving substrate 20 may be formed by an insulating material, semiconductor or conductor, solid or comprising a plurality of layers or functional surface structures (for example cavities), or even comprising all or part of active or passive components.
  • the characteristics of receiving substrate 20 depend mainly on the intended application and the desired functionalities.
  • the receiving substrate 20 can be in the form of a wafer with a diameter of 100mm to 450mm and a thickness of between 250 and 850 microns for example.
  • the removable structure 100 according to the invention is intended to be separated, at the level of the privileged detachment interface 1, so as to transfer the useful layer 3 from the donor substrate 10, to the recipient substrate 20.
  • the mechanical strength of the privileged detachment interface 1 is therefore lower, or even much lower, than the mechanical strength of the assembly interface 30, as is usually the case in a removable structure comprising two interfaces.
  • a difference in mechanical strength or interfacial energy of at least of the order of 1000 mJ / m 2 between the two interfaces 1.30 will be sought.
  • the preferred detachment interface 1 is a bonding interface by molecular adhesion having a first bonding energy E1.
  • the assembly interface 30 can then be a direct bonding interface, by molecular adhesion, by thermocompression or the like, exhibiting a second bonding energy E2, the first bonding energy E1 being less than the second bonding energy E2.
  • the difference between the first E1 and the second E2 bonding energies can be obtained by managing the surface roughness of the faces to be bonded, by the materials brought into contact for bonding by molecular adhesion, by the chemical treatment (wet cleaning or plasma activation) applied to the faces prior to bonding, etc.
  • Materials such as silicon oxide, silicon nitride can be deposited on the faces to be bonded (to form the privileged detachment interface 1 or the assembly interface 30) and treated (cleaning, polishing, plasma activation , etching, ...) so as to adjust the interfacial energy resulting from bonding by molecular adhesion of said faces.
  • the difference in bonding energy (E2-E1) between the two interfaces 1.30 is chosen, at least of the order of 1000 mJ / m 2 .
  • the first bonding energy E1 could be of the order of 2000 mJ / m 2
  • the second bonding energy E2 could be greater than 3000 mJ / m 2 .
  • a bonding energy can in particular be evaluated by measuring the Mazara blade.
  • the removable structure 100 according to the invention is remarkable in that the assembly interface 30 has an assembly interruption zone 31 comprising at least one cavity 31a arranged in the receiving substrate 20 or in the useful layer 3.
  • the assembly interruption zone 31 corresponds to a zone where the assembly interface is interrupted, that is to say that there is no contact between the receiving substrate 20 and the useful layer 3.
  • the assembly interruption zone 31 is located in a peripheral region of the removable structure 100.
  • the assembly interruption zone 31 is located less than 10mm from the edges 100a of said structure 100.
  • the zone assembly interruption 31 is even positioned less than 8mm from the edges 100a of the removable structure, or even less than 5mm, or even less than 3mm.
  • the removable structures 100 formed from the assembly of two microelectronic grade 10,20 wafers have a peripheral exclusion zone 100b, not glued, linked to the edge geometry of said wafers (chamfer) or to the edge geometry of the useful layer 3 present on one of the two plates; this exclusion zone 100b rarely exceeds 1mm to 2mm.
  • the assembly interruption zone 31 is offset radially towards the interior of the removable structure 100 with respect to said exclusion zone 100b, since it must, by definition, interrupt the assembly interface 30 which brings the receiving substrate 20 into contact with the useful layer 3. It could for example be positioned at 0.5mm, 1mm or 2mm from the exclusion zone 100b.
  • the assembly interruption zone 31 is very localized, that is to say that it does not extend, in the peripheral region, along the entire perimeter of the removable structure 100, but only over a length from a few hundred microns (200 microns typically) to a few tens of millimeters (50mm to 100mm typically), for example between 1mm and 20mm, preferably between 5mm and 15mm. This has the advantage of limiting its impact on the usable surface of the useful layer 3.
  • the assembly interruption zone 31 comprises at least one cavity 31a formed either in the receiving substrate 20 (as illustrated in FIG. La), or in the useful layer 3 (as illustrated in FIG. 2a). It should be noted that in the case where the (at least one) cavity 31a is arranged in the useful layer 3, its depth may for example vary between 5% and 95% of the thickness of the useful layer 3, of course never exceeding in depth the thickness of said layer 3.
  • the assembly interruption zone 31 comprises a plurality of cavities 31a.
  • the cavities 31a can for example be spaced from each other by a distance of between 1 micron and 1 mm, typically between a few microns and a few hundred microns, for example 500 microns. They can be aligned on a straight line or on a curved line in the (x, y) plane parallel to the assembly interface 30.
  • the straight line is preferably parallel to the edge 100a of the removable structure 100 or parallel to the tangent. T at said edge 100a (figures lb and 2c).
  • the curved line may have a convex curvature oriented towards the center of the removable structure 100; in other words, as can be seen in the example of FIG. 2b, the curved line follows a curvature opposite to that of the edges 100a of the removable structure 100.
  • the cavity 31a has lateral dimensions of between a few microns and a few millimeters, and typically between 20microns and 1mm. It can also have a depth of between 0.5 microns and several tens of microns, typically up to 20 microns, 50 microns, or even up to 100 microns; for example the cavity 31a can have a depth of 3 microns.
  • the percentage of the contact zones between the receiver substrate 20 and the useful layer 3 is preferably less than 80%, or even less than 50%.
  • the (at least one) cavity 31a of the assembly interruption zone 31 may have, in a plane (x, y) parallel to the assembly interface 30, a square, rectangular, triangular, trapezoidal or rounded periphery. .
  • At least one rectilinear segment of the periphery of the cavity 31a is parallel to a dismantling edge 100a 'of the removable structure 100 or to the tangent T to a dismantling edge 100a' of the removable structure 100.
  • a rectilinear segment of the periphery of the cavity 31a which has the greatest lateral dimension, is parallel to a dismantling edge 100a 'of the dismantling structure 100 or to the tangent T to a dismantling edge 100a' of the removable structure 100.
  • the long side of the cavities 31a in the plane (x, y) would be arranged parallel to the tangent T.
  • the shape of the cavity 31a is not symmetrical, there is a preferred direction for orienting the pattern of the cavity 31a with respect to the dismantling edge 100a '(or to its tangent T) or more precisely with respect to the direction of propagation of the separation wave, as will be described with reference to the transfer method according to the invention. It appears more advantageous for a segment of larger dimension to be crossed last by the separation wave. In the example of FIG. 2c, if the cavities 31a of the assembly interruption zone 31 have a triangular periphery, it is therefore advantageous to position them so that the vertex of the triangle points towards the dismantling edge 100a ' .
  • the invention also relates to a method of transferring a useful layer 3 from a donor substrate 10 onto a recipient substrate 20.
  • the method firstly comprises a step a) of providing a removable structure 100 as described above.
  • step a) comprises the sub-steps below, referenced al) to a4).
  • a step a1) consists in providing the donor substrate 10 which comprises the useful layer 3 placed on the initial substrate 2, the privileged detachment interface 1 being located between said useful layer 3 and said initial substrate 2 (figure 3a).
  • the useful layer 3 of the donor substrate 10 can be produced by any known layer transfer technique, for example:
  • the useful layer 3 comes from a useful substrate bonded to the initial substrate and then thinned.
  • the useful layer 3 also comes from a useful substrate implanted in light species, bonded to the initial substrate, then separated at the level of the buried fragile plane defined by the implantation.
  • the bonding mentioned in these different techniques lead to the development of the preferred detachment interface 1. It is therefore necessary to adjust the bonding parameters (materials in contact, roughness of the surfaces to be bonded, cleaning and chemical activation treatments. surfaces to be bonded, etc.) so as to obtain the first bonding energy (or first interfacial energy) E1 in the desired range, after the donor substrate 10 has potentially undergone heat treatments. This is in particular the case when films are deposited, and / or functional structures are made, and / or all or part of components are produced on or in the useful layer 3, before its transfer to the receiving substrate 20.
  • the first bonding energy (or first interfacial energy) E1 is between 1000 mJ / m 2 and 3000 mJ / m 2 .
  • an energy difference of at least 1000 mJ / m 2 will advantageously be aimed at between the privileged detachment interface 1 (energy El) and the assembly interface 30, which will be formed in a subsequent step. a4) of the process.
  • Step a2) of the method consists in providing the receiving substrate 20, the characteristics of which depend on the intended application and the desired functionalities as mentioned above (FIG. 3b).
  • the following step a3) comprises the formation of one or more cavity (s) 31a opening at the level of a face to be assembled 20c of the receiving substrate 20 (FIG. 3c (i)) or at the level of a face to be assembled 3c of the useful layer 3 (FIG. 3c (ii)), in a peripheral region respectively of the receiving substrate 20 or of the useful layer 3.
  • This (at least one) cavity 31a will make it possible to form the assembly interruption zone 31 when the donor substrate 10 will be assembled on the recipient substrate 20.
  • the assembly interruption zone 31 is located in a peripheral region of the donor substrate 10 or of the recipient substrate 20, less than 10 mm from the edges.
  • the assembly interruption zone 31 is even positioned less than 8mm from the edges of said substrates, less than 5mm, or even less than 3mm.
  • the assembly interruption zone 31 is preferably very localized, that is to say that it does not extend, in the peripheral region, along the entire periphery of the donor substrate 10 or of the recipient substrate 20, but only over a length of a few hundred microns to a few tens of millimeters.
  • each cavity 31a preferably has lateral dimensions of between a few microns and a few millimeters, a depth of between 0.5 microns and several tens of microns and various shapes in the (x, y) plane.
  • a step a4) comprises the assembly of the useful layer 3 and of the receiving substrate 20 at the level of their respective faces to be assembled 3c, 20c, to form the removable structure 100 (FIG. 3d (i) and (ii)).
  • the assembly of the two substrates can be carried out by direct bonding by molecular adhesion, by metal bonding or by adhesive bonding, depending on the intended application and the compatibility of said bondings.
  • Step a4) can comprise, prior to bringing the substrates 10, 20 into contact, sequences of cleaning, deposition of layers favorable to bonding, surface activation or other surface preparations.
  • Step a4) can comprise, after bringing the substrates 10,20 into contact, heat treatments consolidation of the assembly interface 30, at more or less high temperature, depending on the type of bonding and the nature of the materials assembled and composing the substrates 10.20.
  • the assembly interface 30 formed at the end of this step a4) has a bonding energy E2 greater than the bonding energy E1 of the privileged detachment interface 1.
  • the difference between the energy bonding E2 and the bonding energy E1 is of the order of 1000mJ / m 2 , or even greater.
  • the method according to the invention comprises a step b) consisting in the application of a mechanical stress at an edge of dismantling 100a 'of the removable structure 100 (FIG. 3e (i) and (ii)).
  • the dismantling edge 100a ' is located closest to the assembly interruption zone 31 and the mechanical stress is able to initiate a separation wave in the assembly interface 30 or in the privileged detachment interface 1
  • mechanical stress can be applied by inserting a bevel 40 between the edges of the assembled donor 10 and recipient 20 substrates. It can alternatively be applied by injection of a liquid or gaseous fluid between these same edges, or by any other suitable technique.
  • the direction of the propagation wave is in the plane (x, y) and perpendicular to the dismantling edge 100a 'or to the tangent T to the dismantling edge 100a'.
  • a removable structure 100 it is usual for a removable structure 100 to have a peripheral exclusion zone, due to the edge geometry of the donor 10 and recipient 20 substrates. Note that this exclusion zone is not shown on FIGS. 3a to 3g for the sake of simplicity.
  • a mechanical stress for example by inserting a bevel 40 it is possible that the separation wave 41 starts at the assembly interface 30, despite the lower mechanical strength of the interface. of privileged detachment 1. This start of the separation wave 41 in the assembly interface 30 is in particular favored by the presence of the exclusion zone, which gives direct access to said interface 30.
  • step c the method according to the invention continues with step c), during which, if the initiation of the separation wave 41 takes place at the assembly interface 30, a deviation of the Separation wave in the privileged detachment interface 1 occurs when the separation wave 41 passes through the assembly interruption zone 31 (Fig. 3f (i) and (ii)).
  • the cavities 31a of the assembly interruption zone 31 make it possible to modify the stress field at the head of the front of the separation wave 41, favoring its deviation towards the interface of lower energy, by the occurrence the privileged detachment interface 1.
  • the mechanical stress is applied so that the direction of propagation of the separation wave 41, parallel to the y axis in the figures, is perpendicular to at least one rectilinear segment of a periphery of the (or of) cavity (s) 31a of the assembly interruption zone 31 (FIG. 4a).
  • the mechanical stress is applied so that the direction of propagation of the separation wave 41 is perpendicular to a rectilinear segment of a periphery of the cavity 31a which has the largest lateral dimension.
  • This case may for example be encountered when the cavity (s) 31a has (have) a rectangular shape.
  • the the largest dimension of the rectangle (length) will preferably be oriented so as to be perpendicular to the direction of propagation of the separation wave 41.
  • the separation wave 41 when the separation wave 41 is initiated directly in the privileged detachment interface 1 in step b), the passage of said wave at the level of the assembly interruption zone 31 does not modify not its location: after crossing the interruption zone 31, the separation wave 41 continues to propagate at the privileged detachment interface 1.
  • the transfer method then comprises a step d) of propagation of the separation wave at the level of the privileged detachment interface 1, to result in the total separation of the removable structure 100 (FIGS. 3g (i) and 3g (ii )).
  • the separation wave 41 easily propagates along the privileged detachment interface 1, of lower mechanical strength, or spontaneously, the mechanical stress applied to initiate the separation wave 41 being sufficient to propagate the separation wave, either by continuously or intermittently maintaining the application of mechanical stress.
  • FIG. 4b shows a photo in top view, of a useful layer 3 (in silicon) transferred onto a receiving substrate 20 (in silicon) from a removable structure 100 according to invention.
  • the photo shows in particular a zoom around the assembly interruption zone 31, which is formed in the receiving substrate 20.
  • the deviation of the separation wave between the assembly interface 30 is observed (direct bonding of oxide type SiO 2 / silicon) upstream of the assembly interruption zone 31, and the privileged detachment interface (direct bonding of the SiO 2 / Si02 type), downstream of the assembly interruption zone 31.
  • the useful layer 3 is transferred onto the receiving substrate 20.
  • the eight cavities 31a forming the assembly interruption zone 31 are square in shape, with lateral dimensions of 500 microns. x 500 microns and 3 microns deep. They are located about 3mm from the edge.
  • the transfer method applied to the removable structure 100 according to the present invention makes it possible to effectively deflect the separation wave 41, from the assembly interface 30 of the removable structure 100 to the privileged detachment interface. It is thus possible to maximize the surface transferred from the useful layer 3 to a receiving substrate 20 and to transfer a useful layer 3 of high quality.
  • the privileged detachment interface 1 could be constituted by a buried fragile plane obtained by implantation of light species, or by formation of a layer of porous material (for example porous silicon), or even by formation of multilayer deposits. one interface of which has low energy (for example as described in application FR3082997).
  • the present method applies as soon as the removable structure 100 comprises two interfaces 1.30 exhibiting a sufficient difference in interfacial energy, in particular greater than or equal to 1000 mJ / m 2 .

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Abstract

The invention relates to a removable structure (100) comprising: - at least two interfaces, an assembly interface (30) and a privileged detachment interface (1), - a receiver substrate (20), - a donor substrate (10) comprising a useful layer (3) to be transferred that is disposed on an initial substrate (2), the privileged detachment interface (1) being located between said useful layer (3) and the initial substrate (2), and the assembly interface (30) being located between said useful layer (3) and the receiver substrate (20). The removable structure (100) is characterised in that the assembly interface (30) has an assembly interruption zone (31) comprising at least one cavity (31a) present in the receiver substrate (20) or in the useful layer (3), the assembly interruption zone (31) being located in a peripheral region of the removable structure (100).

Description

STRUCTURE DEMONTABLE UTILISEE POUR LE TRANSFERT OU LA MANIPULATION DE COUCHES, ET PROCEDE DE TRANSFERT D'UNE COUCHE METTANT EN ŒUVRE LADITE STRUCTURE DEMONTABLE DISMOUNTABLE STRUCTURE USED FOR THE TRANSFER OR HANDLING OF LAYERS, AND PROCESS FOR TRANSFERING A LAYER IMPLEMENTING THE SAID DISMOUNTABLE STRUCTURE
DOMAINE DE L' INVENTION FIELD OF THE INVENTION
La présente invention concerne le domaine du transfert de couches minces pour les applications microélectroniques, optiques, microsystèmes, etc. Elle concerne en particulier une structure démontable pouvant être utilisée pour le transfert ou la manipulation de couches minces. The present invention relates to the field of thin film transfer for microelectronic, optical, microsystems, etc. applications. It relates in particular to a removable structure that can be used for the transfer or handling of thin layers.
ARRIERE PLAN TECHNOLOGIQUE DE L' INVENTION TECHNOLOGICAL BACKGROUND OF THE INVENTION
De nombreuses applications, notamment dans les domaines microélectroniques, optiques ou microsystèmes, requièrent des couches minces (intégrant potentiellement des composants) disposées sur des substrats spécifiques (fins, souples, métalliques, isolants, etc). Ces substrats spécifiques ne sont pas toujours compatibles avec les procédés de fabrication des couches minces et/ou les procédés d'intégration de composants sur lesdites couches. Numerous applications, in particular in the microelectronic, optical or microsystems fields, require thin layers (potentially integrating components) arranged on specific substrates (thin, flexible, metallic, insulating, etc.). These specific substrates are not always compatible with the processes for manufacturing thin layers and / or the processes for integrating components on said layers.
Il est donc intéressant de pouvoir transférer une couche mince (avec ou sans des composants intégrés) d'un substrat initial compatible avec les procédés précédemment évoqués, vers un substrat spécifique cible présentant les propriétés requises pour l'application visée. It is therefore advantageous to be able to transfer a thin layer (with or without integrated components) from an initial substrate compatible with the previously mentioned methods, to a specific target substrate having the properties required for the intended application.
Il existe plusieurs procédés de transfert sur un substrat cible, d'une couche mince élaborée sur un substrat initial. Certains procédés de transfert consistent à assembler la couche mince (disposée sur le substrat initial) et le substrat cible, puis à éliminer mécaniquement et/ou chimiquement le substrat initial, transférant ainsi la couche sur le substrat cible. Les inconvénients principaux de cette approche sont les coûts liés à la perte du substrat initial et les traitements mécaniques et chimiques contraignants susceptibles de dégrader la qualité de la couche mince au cours du transfert. There are several methods of transferring to a target substrate, a thin film produced on an initial substrate. Some transfer methods consist of assembling the thin film (placed on the initial substrate) and the target substrate, then mechanically and / or chemically removing the initial substrate, thereby transferring the layer to the target substrate. The main drawbacks of this approach are the costs associated with the loss of the initial substrate and the restrictive mechanical and chemical treatments liable to degrade the quality of the thin film during the transfer.
D'autres procédés sont basés sur une séparation par application d'une contrainte mécanique ou d'un traitement chimique au niveau d'une couche ou d'une interface fragilisée présente entre la couche mince et le substrat initial ; la couche mince préalablement assemblée sur le substrat cible, est transférée sur ce dernier lorsque la séparation s'effectue. C'est notamment le cas des procédés décrits dans les documents FR2748851, FR2823599 ou FR2823596 ; on parle habituellement de structures démontables comportant une couche ou une interface fragilisée, dans laquelle peut s'opérer une séparation, de manière à libérer une couche mince superficielle et la transférer sur un substrat cible. Other methods are based on a separation by application of a mechanical stress or a chemical treatment at the level of a weakened layer or interface present between the thin layer and the initial substrate; the thin layer previously assembled on the target substrate is transferred to the latter when the separation takes place. This is particularly the case with the processes described in documents FR2748851, FR2823599 or FR2823596; one usually speaks of removable structures comprising a weakened layer or interface, in which a separation can take place, so as to release a thin surface layer and transfer it to a target substrate.
Une difficulté liée à ces approches est que le détachement peut parfois se faire au niveau d'interfaces ou de couches autres que celle fragilisée car la contrainte mécanique et/ou l'attaque chimique peuvent difficilement être localisées précisément au niveau de ladite couche ou interface fragilisée. Les variabilités de géométrie des bords de substrats, la méthode d'application de la contrainte mécanique ou de la solution de gravure chimique pour le démontage peuvent induire le démarrage de la séparation à une autre interface que celle fragilisée, même si cette autre interface présente une tenue mécanique supérieure à la tenue de l'interface fragilisée. Pour résoudre ce problème, il est envisageable de renforcer localement, notamment en bords de substrats, la tenue mécanique des interfaces autres que celle fragilisée et/ou de diminuer davantage la tenue de ladite interface fragilisée. Ces dispositions ne permettent néanmoins pas toujours d'empêcher l'initiation de la séparation au niveau d'une interface non visée. A difficulty associated with these approaches is that the detachment can sometimes be done at the level of interfaces or layers other than the weakened one because the mechanical stress and / or the chemical attack can hardly be localized precisely at the level of said weakened layer or interface. . The variability of the geometry of the edges of the substrates, the method of applying the mechanical stress or the chemical etching solution for the dismantling can induce the start of the separation at an interface other than the weakened one, even if this other interface has a mechanical strength greater than the strength of the weakened interface. To resolve this problem, it is conceivable to locally reinforce, in particular at the edges of substrates, the mechanical strength of interfaces other than the weakened one and / or to further reduce the strength of said weakened interface. However, these arrangements do not always make it possible to prevent the initiation of separation at a non-target interface.
Le document FR2995446 adresse les structures démontables comprenant au moins deux interfaces, dont celle fragilisée au niveau de laquelle la séparation est attendue. Il propose des solutions pour rediriger le front de séparation vers l'interface fragilisée lorsque celui-ci démarre au niveau de l'autre interface. Document FR2995446 addresses removable structures comprising at least two interfaces, including the weakened one at which separation is expected. It offers solutions for redirecting the separation front towards the weakened interface when the latter starts at the level of the other interface.
OBJET DE L' INVENTION OBJECT OF THE INVENTION
La présente invention concerne une solution alternative aidant à localiser le détachement au niveau de l'interface fragilisée d'une structure démontable. Un objet de l'invention est une structure démontable comprenant au moins deux interfaces dont l'une est l'interface fragilisée ou interface de détachement privilégié. Ladite structure démontable est utilisée pour le transfert ou la manipulation de couches. The present invention relates to an alternative solution helping to localize the detachment at the weakened interface of a removable structure. An object of the invention is a removable structure comprising at least two interfaces, one of which is the weakened interface or the privileged detachment interface. Said removable structure is used for the transfer or handling of layers.
BREVE DESCRIPTION DE L' INVENTION BRIEF DESCRIPTION OF THE INVENTION
La présente invention concerne une structure démontable pour le transfert ou la manipulation de couches, comprenant : The present invention relates to a removable structure for transferring or handling layers, comprising:
- au moins deux interfaces, une interface d'assemblage et une interface de détachement privilégié, - at least two interfaces, an assembly interface and a privileged detachment interface,
- un substrat receveur, - un substrat donneur comportant une couche utile à transférer disposée sur un substrat initial, l'interface de détachement privilégié étant située entre ladite couche utile et le substrat initial, et l'interface d'assemblage étant située entre ladite couche utile et le substrat receveur. - a receiving substrate, a donor substrate comprising a useful layer to be transferred placed on an initial substrate, the privileged detachment interface being located between said useful layer and the initial substrate, and the assembly interface being located between said useful layer and the recipient substrate .
La structure démontable est remarquable en ce que l'interface d'assemblage présente une zone d'interruption d'assemblage comprenant au moins une cavité présente dans le substrat receveur ou dans la couche utile, dans ce dernier cas, la profondeur de la cavité étant strictement inférieure à l'épaisseur de la couche utile. La zone d'interruption d'assemblage est localisée dans une région périphérique de la structure démontable, elle permet de modifier un champ de contrainte en tête du front d'une onde de séparation lorsque cette dernière est initiée dans l'interface d'assemblage pour le transfert ou la manipulation de la couche utile. The removable structure is remarkable in that the assembly interface has an assembly interruption zone comprising at least one cavity present in the receiving substrate or in the useful layer, in the latter case, the depth of the cavity being strictly less than the thickness of the useful layer. The assembly interruption zone is located in a peripheral region of the dismountable structure, it makes it possible to modify a stress field at the head of the front of a separation wave when the latter is initiated in the assembly interface to the transfer or manipulation of the useful layer.
La modification du champ de contrainte par la -au moins une- cavité de la zone d'interruption d'assemblage permet la déviation de l'onde de séparation, de l'interface d'assemblage vers l'interface de détachement privilégié, autorisant ainsi un report de la couche utile sur le substrat receveur. The modification of the stress field by the -at least one- cavity of the assembly interruption zone allows the deviation of the separation wave, from the assembly interface to the privileged detachment interface, thus allowing a transfer of the useful layer on the receiving substrate.
Selon des caractéristiques avantageuses de l'invention, prises seules ou selon toute combinaison réalisable : According to advantageous characteristics of the invention, taken alone or in any feasible combination:
• la zone d'interruption d'assemblage s'étend sur une longueur, le long du pourtour de la structure démontable, inférieure ou égale à 20mm ; • the assembly interruption zone extends over a length, along the perimeter of the removable structure, less than or equal to 20mm;
• la zone d'interruption d'assemblage est située à moins de 10mm des bords de la structure démontable ; • the assembly interruption zone is located less than 10mm from the edges of the dismantling structure;
• la (au moins une) cavité présente des dimensions latérales comprises entre quelques microns et quelques millimètres, préférentiellement entre 20 microns et 1mm ; • la (au moins une) cavité présente une profondeur comprise entre 0,5 micron et plusieurs dizaines de microns, typiquement 50 microns ; • the (at least one) cavity has lateral dimensions of between a few microns and a few millimeters, preferably between 20 microns and 1mm; • the (at least one) cavity has a depth of between 0.5 microns and several tens of microns, typically 50 microns;
• la (au moins une) cavité présente, dans un plan parallèle à l'interface d'assemblage, un pourtour carré, rectangulaire, triangulaire, trapézoïdal ou arrondi ; • the (at least one) cavity has, in a plane parallel to the assembly interface, a square, rectangular, triangular, trapezoidal or rounded periphery;
• au moins un segment rectiligne du pourtour de la (au moins une) cavité est parallèle à un bord de démontage de la structure démontable ou à la tangente à un bord de démontage de la structure démontable ; • at least one rectilinear segment of the perimeter of the (at least one) cavity is parallel to a dismantling edge of the removable structure or to the tangent to a dismantling edge of the removable structure;
• un segment rectiligne du pourtour de la (au moins une) cavité, qui présente la plus grande dimension latérale, est parallèle à un bord de démontage de la structure démontable ou à la tangente à un bord de démontage de la structure démontable ; • a rectilinear segment of the perimeter of the (at least one) cavity, which has the largest lateral dimension, is parallel to a dismantling edge of the removable structure or to a tangent to a dismantling edge of the dismantled structure;
• la zone d'interruption d'assemblage comprend une pluralité de cavités espacées entre elles d'une distance comprise entre 1 micron et 1mm, typiquement entre quelques microns et quelques centaines de microns ; • the assembly interruption zone comprises a plurality of cavities spaced apart by a distance of between 1 micron and 1mm, typically between a few microns and a few hundred microns;
• le pourcentage de zones de contact, entre les cavités, de la zone d'interruption d'assemblage, est inférieur à 80%, voire inférieur à 50% ; • the percentage of contact zones, between the cavities, of the assembly interruption zone, is less than 80%, or even less than 50%;
• les cavités sont alignées suivant une ligne droite ou suivant une ligne courbe, dont la convexité est orientée vers le centre de la structure démontable ; • the cavities are aligned along a straight line or along a curved line, the convexity of which is oriented towards the center of the removable structure;
• la zone d'interruption d'assemblage est positionnée à moins de 8mm des bords de la structure démontable, voire à moins de 3 mm ; • the assembly interruption zone is positioned less than 8mm from the edges of the removable structure, or even less than 3mm;
• la couche utile présente une épaisseur comprise entre quelques centaines de nanomètres et plusieurs centaines de microns, typiquement entre 200nm et 200 microns ; • the useful layer has a thickness between a few hundred nanometers and several hundred microns, typically between 200 nm and 200 microns;
• l'interface de détachement privilégié présente une première énergie interfaciale, l'interface d'assemblage présente une deuxième énergie interfaciale, et l'écart d'énergie interfaciale entre l'interface de détachement privilégié et l'interface d'assemblage est supérieur ou égale à 1000mJ/m2 ; • the privileged detachment interface presents a first interfacial energy, the assembly interface presents a second interfacial energy, and the difference in interfacial energy between the privileged detachment interface and the assembly interface is greater than or equal to 1000 mJ / m 2 ;
• l'interface de détachement privilégié est une interface de collage par adhésion moléculaire présentant une première énergie de collage, et l'interface d'assemblage est une interface de collage par adhésion moléculaire présentant une deuxième énergie de collage, la première énergie de collage étant inférieure à la deuxième énergie de collage ; • the preferred detachment interface is a bonding interface by molecular adhesion having a first bonding energy, and the assembly interface is a bonding interface by molecular adhesion having a second bonding energy, the first bonding energy being less than the second bonding energy;
• l'écart d'énergie de collage entre l'interface de détachement privilégié et l'interface d'assemblage est au moins de l'ordre de 1000mJ/m2. • the difference in bonding energy between the privileged detachment interface and the assembly interface is at least of the order of 1000 mJ / m 2 .
L'invention concerne également un procédé de transfert d'une couche utile d'un substrat donneur sur un substrat receveur, comprenant les étapes suivantes : a) la fourniture d'une structure démontable telle que ci-dessus, b) l'application d'une contrainte mécanique au niveau d'un bord de démontage de la structure démontable, ledit bord de démontage étant localisé au plus proche de la zone d'interruption d'assemblage et la contrainte mécanique étant apte à initier une onde de séparation à l'interface d'assemblage ou à l'interface de détachement privilégié, c) si l'initiation de l'onde de séparation s'opère à l'interface d'assemblage, la déviation de l'onde de séparation dans l'interface de détachement privilégié lorsque l'onde de séparation passe au niveau la zone d'interruption d'assemblage, d) la propagation de l'onde de séparation à l'interface de détachement privilégié, pour aboutir à la séparation totale de la structure démontable. Selon des caractéristiques avantageuses de l'invention, prises seules ou selon toute combinaison réalisable : The invention also relates to a method of transferring a useful layer from a donor substrate to a recipient substrate, comprising the following steps: a) providing a removable structure as above, b) applying d 'a mechanical stress at the level of a dismantling edge of the removable structure, said dismantling edge being located closest to the assembly interruption zone and the mechanical stress being able to initiate a separation wave at the assembly interface or at the privileged detachment interface, c) if the initiation of the separation wave occurs at the assembly interface, the deviation of the separation wave in the detachment interface privileged when the separation wave passes through the assembly interruption zone, d) the propagation of the separation wave at the privileged detachment interface, to result in the total separation of the dismountable structure. According to advantageous characteristics of the invention, taken alone or in any feasible combination:
• la contrainte mécanique est appliquée de sorte que la direction de propagation de l'onde de séparation soit perpendiculaire à au moins un segment rectiligne d'un pourtour de la (au moins une) cavité de la zone d'interruption d'assemblage ; • the mechanical stress is applied so that the direction of propagation of the separation wave is perpendicular to at least one rectilinear segment of a periphery of the (at least one) cavity of the assembly interruption zone;
• la contrainte mécanique est appliquée de sorte que la direction de propagation de l'onde de séparation soit perpendiculaire à un segment rectiligne d'un pourtour de la (au moins une) cavité qui présente la plus grande dimension latérale ; • the mechanical stress is applied so that the direction of propagation of the separation wave is perpendicular to a rectilinear segment of a periphery of the (at least one) cavity which has the greatest lateral dimension;
• la contrainte mécanique est appliquée par insertion d'un outil en biseau entre les bords du substrat receveur et les bords du substrat donneur ; • the mechanical stress is applied by inserting a beveled tool between the edges of the recipient substrate and the edges of the donor substrate;
• l'étape a) comprend : o la fourniture du substrat donneur comprenant la couche utile disposée sur le substrat initial, l'interface de détachement privilégié étant située entre ladite couche utile et ledit substrat initial, o la fourniture d'un substrat receveur, o la formation d'au moins une cavité débouchant au niveau d'une face à assembler du substrat receveur ou au niveau d'une face à assembler de la couche utile, dans une région périphérique du substrat receveur ou de la couche utile, o l'assemblage de la couche utile et du substrat receveur au niveau de leurs faces à assembler respectives. • step a) comprises: o the supply of the donor substrate comprising the useful layer placed on the initial substrate, the privileged detachment interface being located between said useful layer and said initial substrate, o the supply of a recipient substrate, the formation of at least one cavity opening at the level of a face to be assembled of the recipient substrate or at the level of a face to be assembled of the useful layer, in a peripheral region of the recipient substrate or of the useful layer, o l assembly of the useful layer and of the receiving substrate at the level of their respective faces to be assembled.
BREVE DESCRIPTION DES DESSINS D'autres caractéristiques et avantages de l'invention ressortiront de la description détaillée qui va suivre en référence aux figures annexées sur lesquelles : BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention will emerge from the detailed description which follows with reference to the appended figures in which:
- Les figures la et lb présentent respectivement une vue en coupe et une vue dans le plan, d'une structure démontable conforme à l'invention ; sur la vue dans le plan, les cavités sont rendues visibles pour une meilleure compréhension de leur distribution et localisation, alors qu'elles devraient être masquées car disposées entre la couche utile et le substrat receveur. - Figures la and lb show respectively a sectional view and a plan view of a removable structure according to the invention; in the plan view, the cavities are made visible for a better understanding of their distribution and location, whereas they should be masked because they are arranged between the useful layer and the receiving substrate.
- Les figures 2a, 2b et 2c présentent respectivement une vue en coupe et deux vues dans le plan, d'une structure démontable conforme à l'invention ; sur les vues dans le plan, les cavités sont rendues visibles pour une meilleure compréhension de leur distribution et localisation, alors qu'elles devraient être masquées car disposées entre la couche utile et le substrat receveur. - Figures 2a, 2b and 2c respectively show a sectional view and two views in the plan, of a removable structure according to the invention; on the views in the plan, the cavities are made visible for a better understanding of their distribution and location, whereas they should be masked because they are placed between the useful layer and the receiving substrate.
- Les figures 3a à 3g présentent des étapes du procédé de transfert conforme à la présente invention ; - Figures 3a to 3g show steps of the transfer method according to the present invention;
- La figure 4a présente une vue dans le plan d'une structure démontable au cours de l'étape d'application d'une contrainte mécanique, étape du procédé de transfert conforme à l'invention ; la figure 4b présente une photo, zoomée autour de la zone d'interruption d'assemblage, du report d'une couche utile sur un substrat receveur à l'issue du procédé de transfert conforme à la présente invention. FIG. 4a shows a plan view of a structure that can be dismantled during the step of applying a mechanical stress, step of the transfer method according to the invention; FIG. 4b shows a photo, zoomed around the assembly interruption zone, of the transfer of a useful layer onto a receiving substrate at the end of the transfer process according to the present invention.
DESCRIPTION DETAILLEE DE L' INVENTION DETAILED DESCRIPTION OF THE INVENTION
Dans la partie descriptive, les mêmes références sur les figures pourront être utilisées pour des éléments de même nature. In the descriptive part, the same references in the figures may be used for elements of the same nature.
Les figures sont des représentations schématiques qui, dans un objectif de lisibilité, ne sont pas à l'échelle. En particulier, les épaisseurs des couches selon l'axe z ne sont pas à l'échelle par rapport aux dimensions latérales selon les axes x et y. The figures are schematic representations which, for the sake of readability, are not to scale. Specifically, the thicknesses of the layers along the z axis are not to scale with respect to the lateral dimensions along the x and y axes.
L'invention concerne une structure démontable 100 comprenant au moins deux interfaces, une interface d'assemblage 30 et une interface de détachement privilégié 1. Sur la figure la, les deux interfaces s'étendent dans des plans parallèles au plan (x,y)· The invention relates to a removable structure 100 comprising at least two interfaces, an assembly interface 30 and a privileged detachment interface 1. In FIG. 1a, the two interfaces extend in planes parallel to the plane (x, y). ·
Par structure démontable, on entend une structure 100 destinée à subir une sollicitation par voie mécanique pour amorcer une séparation, souhaitée au niveau de l'interface de détachement privilégiée 1 ; du fait de la présence de la deuxième interface (interface d'assemblage 30), il y a concurrence de propagation de l'onde de séparation entre les deux interfaces 1,30. The term “removable structure” is understood to mean a structure 100 intended to be subjected to a mechanical stress in order to initiate a separation, desired at the level of the privileged detachment interface 1; due to the presence of the second interface (assembly interface 30), there is competition for propagation of the separation wave between the two interfaces 1.30.
La structure démontable 100 comprend un substrat donneur 10 incluant une couche utile 3 à transférer disposée sur un substrat initial 2 ; l'interface de détachement privilégié 1 est située entre la couche utile 3 et le substrat initial 2. The removable structure 100 comprises a donor substrate 10 including a useful layer 3 to be transferred placed on an initial substrate 2; the privileged detachment interface 1 is located between the useful layer 3 and the initial substrate 2.
A titre d'exemple, la couche utile 3 peut être formée en un matériau semi-conducteur, tel que le silicium, le carbure de silicium, le germanium, un composé III-V, ..., et/ou en un matériau isolant, notamment piézoélectrique, tel que le tantalate de lithium ou le niobate de lithium. Bien sûr, cette liste n'est pas exhaustive et tout matériau en couche mince que l'on aurait intérêt à transférer d'un substrat donneur 10 vers un substrat receveur 20 pourrait former la couche utile 3. By way of example, the useful layer 3 can be formed from a semiconductor material, such as silicon, silicon carbide, germanium, a III-V compound, ..., and / or an insulating material , in particular piezoelectric, such as lithium tantalate or lithium niobate. Of course, this list is not exhaustive and any thin film material that it would be beneficial to transfer from a donor substrate 10 to a recipient substrate 20 could form the useful layer 3.
La couche utile 3 peut également comprendre une pluralité de films de matériaux différents, et/ou des structurations fonctionnelles (par exemple des cavités) en particulier sur sa face en vis-à-vis du substrat receveur 30, et/ou tout ou partie de composants microélectroniques. L'adhérence entre les différents films ou empilements de composants est bien sûr attendue plus élevée que la tenue de l'interface de détachement privilégié 1 dont les caractéristiques seront détaillées plus loin. De manière générale, les caractéristiques de la couche utile 3 dépendent de l'application visée et des fonctionnalités recherchées. The useful layer 3 can also comprise a plurality of films of different materials, and / or functional structures (for example cavities) in particular on its face vis-à-vis the receiving substrate 30, and / or all or part of microelectronic components. The adhesion between the different films or stacks of components is of course expected higher than the holding of the privileged detachment interface 1, the characteristics of which will be detailed below. In general, the characteristics of the useful layer 3 depend on the targeted application and the desired functionalities.
La couche utile 3 présente une épaisseur comprise entre quelques centaines de nanomètres et quelques centaines de microns, par exemple comprise entre 200nm et 200 microns, ou préférentiellement comprise entre 1 micron et 50 microns. The useful layer 3 has a thickness between a few hundred nanometers and a few hundred microns, for example between 200 nm and 200 microns, or preferably between 1 micron and 50 microns.
Le substrat initial 2 est avantageusement formé par un matériau bas coût, procurant un bon support mécanique pour la manipulation de la couche utile 3. Bien que d'autres matériaux puissent être envisagés, le silicium est en général le matériau de choix du fait de sa compatibilité avec toute ligne de fabrication microélectronique . The initial substrate 2 is advantageously formed by a low-cost material, providing good mechanical support for the handling of the useful layer 3. Although other materials can be considered, silicon is generally the material of choice because of its material. compatibility with any microelectronic manufacturing line.
Le substrat initial 2 peut se présenter sous forme de plaquette de diamètre 100mm à 450mm et d'épaisseur comprise entre 250 et 850 microns par exemple. Bien sûr, le substrat initial 2 peut alternativement se présenter sous d'autres formes (carrée par exemple). The initial substrate 2 can be in the form of a wafer with a diameter of 100mm to 450mm and a thickness of between 250 and 850 microns for example. Of course, the initial substrate 2 can alternatively be in other shapes (square for example).
La structure démontable 100 comprend en outre un substrat receveur 20, assemblé sur le substrat donneur 10 : l'interface d'assemblage 30 est située entre le substrat receveur 20 et la couche utile 3. The removable structure 100 further comprises a recipient substrate 20, assembled on the donor substrate 10: the assembly interface 30 is located between the recipient substrate 20 and the useful layer 3.
Le substrat receveur 20 pourra être formé par un matériau isolant, semi-conducteur ou conducteur, massif ou comprenant une pluralité de couches ou des structurations fonctionnelles de surface (par exemple des cavités), ou encore comprenant tout ou partie de composants actifs ou passifs. Les caractéristiques du substrat receveur 20 dépendent principalement de l'application visée et des fonctionnalités recherchées. The receiving substrate 20 may be formed by an insulating material, semiconductor or conductor, solid or comprising a plurality of layers or functional surface structures (for example cavities), or even comprising all or part of active or passive components. The characteristics of receiving substrate 20 depend mainly on the intended application and the desired functionalities.
Comme le substrat initial 2, le substrat receveur 20 peut se présenter sous forme de plaquette de diamètre 100mm à 450mm et d'épaisseur comprise entre 250 et 850 microns par exemple. Like the initial substrate 2, the receiving substrate 20 can be in the form of a wafer with a diameter of 100mm to 450mm and a thickness of between 250 and 850 microns for example.
La structure démontable 100 selon l'invention est destinée à être séparée, au niveau de l'interface de détachement privilégié 1, de manière à transférer la couche utile 3 depuis le substrat donneur 10, sur le substrat receveur 20. The removable structure 100 according to the invention is intended to be separated, at the level of the privileged detachment interface 1, so as to transfer the useful layer 3 from the donor substrate 10, to the recipient substrate 20.
De manière générale, la tenue mécanique de l'interface de détachement privilégié 1 est donc inférieure, voire très inférieure à la tenue mécanique de l'interface d'assemblage 30, comme cela est habituellement le cas dans une structure démontable comprenant deux interfaces. On visera préférentiellement un écart de tenue mécanique ou d'énergie interfaciale au moins de l'ordre de 1000mJ/m2 entre les deux interfaces 1,30. In general, the mechanical strength of the privileged detachment interface 1 is therefore lower, or even much lower, than the mechanical strength of the assembly interface 30, as is usually the case in a removable structure comprising two interfaces. Preferably, a difference in mechanical strength or interfacial energy of at least of the order of 1000 mJ / m 2 between the two interfaces 1.30 will be sought.
Selon un mode de réalisation avantageux, l'interface de détachement privilégié 1 est une interface de collage par adhésion moléculaire présentant une première énergie de collage El. L'interface d'assemblage 30 peut alors être une interface de collage direct, par adhésion moléculaire, par thermocompression ou autre, présentant une deuxième énergie de collage E2, la première énergie de collage El étant inférieure à la deuxième énergie de collage E2. According to an advantageous embodiment, the preferred detachment interface 1 is a bonding interface by molecular adhesion having a first bonding energy E1. The assembly interface 30 can then be a direct bonding interface, by molecular adhesion, by thermocompression or the like, exhibiting a second bonding energy E2, the first bonding energy E1 being less than the second bonding energy E2.
Comme cela est connu en soi, la différence entre la première El et la deuxième E2 énergies de collage pourra être obtenue par la gestion des rugosités de surface des faces à coller, par les matériaux mis en contact pour le collage par adhésion moléculaire, par le traitement chimique (nettoyage humide ou activation plasma) appliqué aux faces préalablement au collage, etc. Des matériaux tels que l'oxyde de silicium, le nitrure de silicium pourront être déposés sur les faces à coller (pour former l'interface de détachement privilégié 1 ou l'interface d'assemblage 30) et traités (nettoyage, polissage, activation plasma, gravure,...) de manière à ajuster l'énergie interfaciale résultant du collage par adhésion moléculaire desdites faces. As is known per se, the difference between the first E1 and the second E2 bonding energies can be obtained by managing the surface roughness of the faces to be bonded, by the materials brought into contact for bonding by molecular adhesion, by the chemical treatment (wet cleaning or plasma activation) applied to the faces prior to bonding, etc. Materials such as silicon oxide, silicon nitride can be deposited on the faces to be bonded (to form the privileged detachment interface 1 or the assembly interface 30) and treated (cleaning, polishing, plasma activation , etching, ...) so as to adjust the interfacial energy resulting from bonding by molecular adhesion of said faces.
Avantageusement, comme énoncé précédemment, l'écart d'énergie de collage (E2-E1) entre les deux interfaces 1,30 est choisi, au moins de l'ordre de 1000mJ/m2. A titre d'exemple, la première énergie de collage El pourra être de l'ordre de 2000 mJ/m2, et la deuxième énergie de collage E2 pourra être supérieure à 3000 mJ/m2. Comme cela est bien connu en soi, nous rappelons qu'une énergie de collage peut notamment être évaluée par la mesure de la lame de Mazara. Advantageously, as stated above, the difference in bonding energy (E2-E1) between the two interfaces 1.30 is chosen, at least of the order of 1000 mJ / m 2 . By way of example, the first bonding energy E1 could be of the order of 2000 mJ / m 2 , and the second bonding energy E2 could be greater than 3000 mJ / m 2 . As is well known per se, we recall that a bonding energy can in particular be evaluated by measuring the Mazara blade.
La structure démontable 100 selon l'invention est remarquable en ce que l'interface d'assemblage 30 présente une zone d'interruption d'assemblage 31 comprenant au moins une cavité 31a aménagée dans le substrat receveur 20 ou dans la couche utile 3. La zone d'interruption d'assemblage 31 correspond à une zone où l'interface d'assemblage est interrompue, c'est-à-dire qu'il n'y a pas de contact entre le substrat receveur 20 et la couche utile 3. The removable structure 100 according to the invention is remarkable in that the assembly interface 30 has an assembly interruption zone 31 comprising at least one cavity 31a arranged in the receiving substrate 20 or in the useful layer 3. The assembly interruption zone 31 corresponds to a zone where the assembly interface is interrupted, that is to say that there is no contact between the receiving substrate 20 and the useful layer 3.
La zone d'interruption d'assemblage 31 est localisée dans une région périphérique de la structure démontable 100. Préférentiellement, la zone d'interruption d'assemblage 31 est située à moins de 10mm des bords 100a de ladite structure 100. Avantageusement, la zone d'interruption d'assemblage 31 est même positionnée à moins de 8mm des bords 100a de la structure démontable, voire à moins de 5mm, voire encore à moins de 3mm. Il est habituel que les structures démontables 100 formées à partir de l'assemblage de deux plaquettes 10,20 de grade microélectronique présentent une zone d'exclusion périphérique 100b, non collée, liée à la géométrie de bord desdites plaquettes (chanfrein) ou à la géométrie de bord de la couche utile 3 présente sur l'une des deux plaquettes ; cette zone d'exclusion 100b excède rarement 1mm à 2mm. En présence de cette zone d'exclusion 100b, la zone d'interruption d'assemblage 31 est décalée radialement vers l'intérieur de la structure démontable 100 par rapport à ladite zone d'exclusion 100b, puisqu'elle doit, par définition, interrompre l'interface d'assemblage 30 qui met en contact le substrat receveur 20 et la couche utile 3. Elle pourra par exemple être positionnée à 0,5mm, 1mm ou 2mm de la zone d'exclusion 100b. The assembly interruption zone 31 is located in a peripheral region of the removable structure 100. Preferably, the assembly interruption zone 31 is located less than 10mm from the edges 100a of said structure 100. Advantageously, the zone assembly interruption 31 is even positioned less than 8mm from the edges 100a of the removable structure, or even less than 5mm, or even less than 3mm. It is usual for the removable structures 100 formed from the assembly of two microelectronic grade 10,20 wafers have a peripheral exclusion zone 100b, not glued, linked to the edge geometry of said wafers (chamfer) or to the edge geometry of the useful layer 3 present on one of the two plates; this exclusion zone 100b rarely exceeds 1mm to 2mm. In the presence of this exclusion zone 100b, the assembly interruption zone 31 is offset radially towards the interior of the removable structure 100 with respect to said exclusion zone 100b, since it must, by definition, interrupt the assembly interface 30 which brings the receiving substrate 20 into contact with the useful layer 3. It could for example be positioned at 0.5mm, 1mm or 2mm from the exclusion zone 100b.
Avantageusement, la zone d'interruption d'assemblage 31 est très localisée, c'est-à-dire qu'elle ne s'étend pas, dans la région périphérique, selon tout le pourtour de la structure démontable 100, mais uniquement sur une longueur de quelques centaines de microns (200 microns typiquement) à quelques dizaines de millimètres (50mm à 100mm typiquement), par exemple entre 1mm et 20mm, préférentiellement entre 5mm et 15mm. Cela présente l'avantage de limiter son impact sur la surface utilisable de la couche utile 3. Advantageously, the assembly interruption zone 31 is very localized, that is to say that it does not extend, in the peripheral region, along the entire perimeter of the removable structure 100, but only over a length from a few hundred microns (200 microns typically) to a few tens of millimeters (50mm to 100mm typically), for example between 1mm and 20mm, preferably between 5mm and 15mm. This has the advantage of limiting its impact on the usable surface of the useful layer 3.
Comme évoqué précédemment, la zone d'interruption d'assemblage 31 comprend au moins une cavité 31a formée soit dans le substrat receveur 20 (comme illustré sur la figure la), soit dans la couche utile 3 (comme illustré sur la figure 2a). Il est à noter que dans le cas où la (au moins une) cavité 31a est aménagée dans la couche utile 3, sa profondeur pourra par exemple varier entre 5% et 95% de l'épaisseur de la couche utile 3, n'excédant bien-sûr jamais en profondeur l'épaisseur de ladite couche 3. As mentioned above, the assembly interruption zone 31 comprises at least one cavity 31a formed either in the receiving substrate 20 (as illustrated in FIG. La), or in the useful layer 3 (as illustrated in FIG. 2a). It should be noted that in the case where the (at least one) cavity 31a is arranged in the useful layer 3, its depth may for example vary between 5% and 95% of the thickness of the useful layer 3, of course never exceeding in depth the thickness of said layer 3.
Avantageusement, la zone d'interruption d'assemblage 31 comprend une pluralité de cavités 31a. Advantageously, the assembly interruption zone 31 comprises a plurality of cavities 31a.
Les cavités 31a peuvent par exemple être espacées entre elles d'une distance comprise entre 1 micron et 1mm, typiquement entre quelques microns et quelques centaines de microns, par exemple 500 microns. Elles peuvent être alignées sur une ligne droite ou sur une ligne courbe dans le plan (x,y) parallèle à l'interface d'assemblage 30. La ligne droite est préférentiellement parallèle au bord 100a de la structure démontable 100 ou parallèle à la tangente T audit bord 100a (figures lb et 2c). La ligne courbe pourra présenter une courbure convexe orientée vers le centre de la structure démontable 100 ; autrement dit, comme cela est visible dans l'exemple de la figure 2b, la ligne courbe suit une courbure opposée à celle des bords 100a de la structure démontable 100. The cavities 31a can for example be spaced from each other by a distance of between 1 micron and 1 mm, typically between a few microns and a few hundred microns, for example 500 microns. They can be aligned on a straight line or on a curved line in the (x, y) plane parallel to the assembly interface 30. The straight line is preferably parallel to the edge 100a of the removable structure 100 or parallel to the tangent. T at said edge 100a (figures lb and 2c). The curved line may have a convex curvature oriented towards the center of the removable structure 100; in other words, as can be seen in the example of FIG. 2b, the curved line follows a curvature opposite to that of the edges 100a of the removable structure 100.
Par la suite, nous parlerons d'une cavité 31a, étant entendu que les caractéristiques énoncées peuvent s'appliquer à toutes les cavités 31a formant la zone d'interruption d'assemblage 31, si celle-ci en comprend une pluralité. Hereinafter, we will talk about a cavity 31a, it being understood that the stated characteristics can be applied to all the cavities 31a forming the assembly interruption zone 31, if the latter comprises a plurality of them.
Avantageusement, la cavité 31a présente des dimensions latérales comprises entre quelques microns et quelques millimètres, et typiquement entre 20microns et 1mm. Elle peut par ailleurs présenter une profondeur comprise entre 0,5 micron et plusieurs dizaines de microns, typiquement jusqu'à 20 microns, 50 microns, voire jusqu'à 100 microns ; par exemple la cavité 31a peut présenter une profondeur de 3 microns. Advantageously, the cavity 31a has lateral dimensions of between a few microns and a few millimeters, and typically between 20microns and 1mm. It can also have a depth of between 0.5 microns and several tens of microns, typically up to 20 microns, 50 microns, or even up to 100 microns; for example the cavity 31a can have a depth of 3 microns.
Lorsque la zone d'interruption d'assemblage 31 comprend une pluralité de cavités 31a, le pourcentage des zones de contact entre le substrat receveur 20 et la couche utile 3 (c'est-à-dire le pourcentage de zones de contact, entre les cavités 31a, de la zone d'interruption d'assemblage 31) est préférentiellement inférieur à 80%, voire inférieur à 50%. When the assembly interruption zone 31 comprises a plurality of cavities 31a, the percentage of the contact zones between the receiver substrate 20 and the useful layer 3 (i.e. the percentage of contact zones, between the cavities 31a, of the assembly interruption zone 31) is preferably less than 80%, or even less than 50%.
La (au moins une) cavité 31a de la zone d'interruption d'assemblage 31 peut présenter, dans un plan (x,y) parallèle à l'interface d'assemblage 30, un pourtour carré, rectangulaire, triangulaire, trapézoïdal ou arrondi. The (at least one) cavity 31a of the assembly interruption zone 31 may have, in a plane (x, y) parallel to the assembly interface 30, a square, rectangular, triangular, trapezoidal or rounded periphery. .
Préférentiellement, au moins un segment rectiligne du pourtour de la cavité 31a est parallèle à un bord de démontage 100a' de la structure démontable 100 ou à la tangente T à un bord de démontage 100a' de la structure démontable 100. Preferably, at least one rectilinear segment of the periphery of the cavity 31a is parallel to a dismantling edge 100a 'of the removable structure 100 or to the tangent T to a dismantling edge 100a' of the removable structure 100.
Selon un autre aspect préférentiel, un segment rectiligne du pourtour de la cavité 31a, qui présente la plus grande dimension latérale, est parallèle à un bord de démontage 100a' de la structure démontable 100 ou à la tangente T à un bord de démontage 100a' de la structure démontable 100. Par exemple, dans le cas de cavités rectangulaire, le grand côté des cavités 31a dans le plan (x,y) serait disposé parallèlement à la tangente T. According to another preferred aspect, a rectilinear segment of the periphery of the cavity 31a, which has the greatest lateral dimension, is parallel to a dismantling edge 100a 'of the dismantling structure 100 or to the tangent T to a dismantling edge 100a' of the removable structure 100. For example, in the case of rectangular cavities, the long side of the cavities 31a in the plane (x, y) would be arranged parallel to the tangent T.
De plus, lorsque la forme de la cavité 31a n'est pas symétrique, il existe un sens préférentiel pour orienter le motif de la cavité 31a par rapport au bord de démontage 100a' (ou à sa tangente T) ou plus précisément par rapport à la direction de propagation de l'onde de séparation, comme cela sera décrit en référence au procédé de transfert selon l'invention. Il apparaît plus avantageux qu'un segment de plus grande dimension soit traversé en dernier lieu par l'onde de séparation. Dans l'exemple de la figure 2c, si les cavités 31a de la zone d'interruption d'assemblage 31 présentent un pourtour triangulaire, il est donc avantageux de les positionner de sorte que le sommet du triangle pointe vers le bord de démontage 100a'. L'invention concerne également un procédé de transfert d'une couche utile 3 d'un substrat donneur 10 sur un substrat receveur 20. In addition, when the shape of the cavity 31a is not symmetrical, there is a preferred direction for orienting the pattern of the cavity 31a with respect to the dismantling edge 100a '(or to its tangent T) or more precisely with respect to the direction of propagation of the separation wave, as will be described with reference to the transfer method according to the invention. It appears more advantageous for a segment of larger dimension to be crossed last by the separation wave. In the example of FIG. 2c, if the cavities 31a of the assembly interruption zone 31 have a triangular periphery, it is therefore advantageous to position them so that the vertex of the triangle points towards the dismantling edge 100a ' . The invention also relates to a method of transferring a useful layer 3 from a donor substrate 10 onto a recipient substrate 20.
Le procédé comprend tout d'abord une étape a) de fourniture d'une structure démontable 100 telle que précédemment décrite. The method firstly comprises a step a) of providing a removable structure 100 as described above.
Selon un mode de réalisation particulier, l'étape a) comporte les sous-étapes ci-après, référencées al) à a4). According to a particular embodiment, step a) comprises the sub-steps below, referenced al) to a4).
Tout d'abord une étape al) consiste en la fourniture du substrat donneur 10 qui comprend la couche utile 3 disposée sur le substrat initial 2, l'interface de détachement privilégié 1 étant située entre ladite couche utile 3 et ledit substrat initial 2 (figure 3a). First of all, a step a1) consists in providing the donor substrate 10 which comprises the useful layer 3 placed on the initial substrate 2, the privileged detachment interface 1 being located between said useful layer 3 and said initial substrate 2 (figure 3a).
La couche utile 3 du substrat donneur 10 peut être élaborée par toute technique de report de couche connue, par exemple : The useful layer 3 of the donor substrate 10 can be produced by any known layer transfer technique, for example:
- par collage puis amincissement mécano-chimique basé sur des techniques de rectification, de polissage, de gravure chimique et de nettoyage ; dans ce cas, la couche utile 3 est issue d'un substrat utile collé sur le substrat initial puis aminci. - by bonding then mechanical-chemical thinning based on grinding, polishing, chemical etching and cleaning techniques; in this case, the useful layer 3 comes from a useful substrate bonded to the initial substrate and then thinned.
- par le procédé Smart Cut®, pour le report de couche mince, typiquement d'épaisseur inférieure à 2 microns ; dans ce cas, la couche utile 3 est également issue d'un substrat utile implanté en espèces légères, collé sur le substrat initial, puis séparé au niveau du plan fragile enterré défini par l'implantation.- by the Smart Cut® process, for the transfer of a thin layer, typically with a thickness of less than 2 microns; in this case, the useful layer 3 also comes from a useful substrate implanted in light species, bonded to the initial substrate, then separated at the level of the buried fragile plane defined by the implantation.
- par le procédé Smart Cut® suivi d'une étape d'épitaxie ou de dépôt visant à épaissir la couche utile reportée. Les collages évoqués dans ces différentes techniques mènent à l'élaboration de l'interface de détachement privilégié 1. Il est donc nécessaire d'ajuster les paramètres de collage (matériaux en contact, rugosités des surfaces à coller, nettoyages et traitements chimiques d'activation des surfaces à coller...) de manière à obtenir la première énergie de collage (ou première énergie interfaciale) El dans la gamme souhaitée, après que le substrat donneur 10 ait potentiellement subi des traitements thermiques. Cela est notamment le cas lorsque des films sont déposés, et/ou que des structurations fonctionnelles sont faites, et/ou que tout ou partie de composants sont élaborés sur ou dans la couche utile 3, avant son transfert sur le substrat receveur 20. - by the Smart Cut® process followed by an epitaxy or deposition step aimed at thickening the useful transferred layer. The bonding mentioned in these different techniques lead to the development of the preferred detachment interface 1. It is therefore necessary to adjust the bonding parameters (materials in contact, roughness of the surfaces to be bonded, cleaning and chemical activation treatments. surfaces to be bonded, etc.) so as to obtain the first bonding energy (or first interfacial energy) E1 in the desired range, after the donor substrate 10 has potentially undergone heat treatments. This is in particular the case when films are deposited, and / or functional structures are made, and / or all or part of components are produced on or in the useful layer 3, before its transfer to the receiving substrate 20.
Préférentiellement, la première énergie de collage (ou première énergie interfaciale) El est comprise entre 1000mJ/m2 et 3000mJ/m2. Comme cela a été énoncé précédemment, on visera avantageusement un écart d'énergie de 1000mJ/m2 au moins entre l'interface de détachement privilégié 1 (énergie El) et l'interface d'assemblage 30, qui sera formée dans une étape ultérieure a4) du procédé. Preferably, the first bonding energy (or first interfacial energy) E1 is between 1000 mJ / m 2 and 3000 mJ / m 2 . As stated previously, an energy difference of at least 1000 mJ / m 2 will advantageously be aimed at between the privileged detachment interface 1 (energy El) and the assembly interface 30, which will be formed in a subsequent step. a4) of the process.
L'étape a2) du procédé consiste en la fourniture du substrat receveur 20, dont les caractéristiques dépendent de l'application visée et des fonctionnalités recherchées comme précédemment évoqué (figure 3b). Step a2) of the method consists in providing the receiving substrate 20, the characteristics of which depend on the intended application and the desired functionalities as mentioned above (FIG. 3b).
L'étape a3) suivante comprend la formation d'une ou plusieurs cavité (s) 31a débouchant au niveau d'une face à assembler 20c du substrat receveur 20 (figure 3c(i)) ou au niveau d'une face à assembler 3c de la couche utile 3 (figure 3c(ii)), dans une région périphérique respectivement du substrat receveur 20 ou de la couche utile 3. Cette (au moins une) cavité 31a permettra de former la zone d'interruption d'assemblage 31 lorsque le substrat donneur 10 sera assemblé sur le substrat receveur 20. La zone d'interruption d'assemblage 31 est localisée dans une région périphérique du substrat donneur 10 ou du substrat receveur 20, à moins de 10mm des bords. Avantageusement, la zone d'interruption d'assemblage 31 est même positionnée à moins de 8mm des bords desdits substrats, à moins de 5mm, voire à moins de 3mm. The following step a3) comprises the formation of one or more cavity (s) 31a opening at the level of a face to be assembled 20c of the receiving substrate 20 (FIG. 3c (i)) or at the level of a face to be assembled 3c of the useful layer 3 (FIG. 3c (ii)), in a peripheral region respectively of the receiving substrate 20 or of the useful layer 3. This (at least one) cavity 31a will make it possible to form the assembly interruption zone 31 when the donor substrate 10 will be assembled on the recipient substrate 20. The assembly interruption zone 31 is located in a peripheral region of the donor substrate 10 or of the recipient substrate 20, less than 10 mm from the edges. Advantageously, the assembly interruption zone 31 is even positioned less than 8mm from the edges of said substrates, less than 5mm, or even less than 3mm.
La zone d'interruption d'assemblage 31 est préférentiellement très localisée, c'est-à-dire qu'elle ne s'étend pas, dans la région périphérique, selon tout le pourtour du substrat donneur 10 ou du substrat receveur 20, mais uniquement sur une longueur de quelques centaines de microns à quelques dizaines de millimètres. The assembly interruption zone 31 is preferably very localized, that is to say that it does not extend, in the peripheral region, along the entire periphery of the donor substrate 10 or of the recipient substrate 20, but only over a length of a few hundred microns to a few tens of millimeters.
La formation de la cavité 31a peut être réalisée par des techniques classiques de lithographie et gravure. Comme énoncé précédemment, chaque cavité 31a présente préférentiellement des dimensions latérales comprises entre quelques microns et quelques millimètres, une profondeur comprise entre 0,5 micron et plusieurs dizaines de microns et des formes variées dans le plan (x,y). The formation of the cavity 31a can be carried out by conventional lithography and etching techniques. As stated above, each cavity 31a preferably has lateral dimensions of between a few microns and a few millimeters, a depth of between 0.5 microns and several tens of microns and various shapes in the (x, y) plane.
Enfin, une étape a4) comprend l'assemblage de la couche utile 3 et du substrat receveur 20 au niveau de leurs faces à assembler 3c, 20c respectives, pour former la structure démontable 100 (figure 3d (i) et (ii)). Finally, a step a4) comprises the assembly of the useful layer 3 and of the receiving substrate 20 at the level of their respective faces to be assembled 3c, 20c, to form the removable structure 100 (FIG. 3d (i) and (ii)).
Comme cela est bien connu en soi, l'assemblage des deux substrats peut être réalisé par collage direct par adhésion moléculaire, par collage métallique ou par collage adhésif, selon l'application visée et la compatibilité desdits collages. L'étape a4) peut comprendre préalablement à la mise en contact des substrats 10,20 des séquences de nettoyages, de dépôt de couches favorables au collage, d'activation de surface ou autres préparations de surface. L'étape a4) peut comprendre après la mise en contact des substrats 10,20, des traitements thermiques de consolidation de l'interface d'assemblage 30, à plus ou moins haute température, selon le type de collage et la nature des matériaux assemblés et composant les substrats 10,20. As is well known per se, the assembly of the two substrates can be carried out by direct bonding by molecular adhesion, by metal bonding or by adhesive bonding, depending on the intended application and the compatibility of said bondings. Step a4) can comprise, prior to bringing the substrates 10, 20 into contact, sequences of cleaning, deposition of layers favorable to bonding, surface activation or other surface preparations. Step a4) can comprise, after bringing the substrates 10,20 into contact, heat treatments consolidation of the assembly interface 30, at more or less high temperature, depending on the type of bonding and the nature of the materials assembled and composing the substrates 10.20.
L'interface d'assemblage 30 formée à l'issue de cette étape a4) présente une énergie de collage E2 supérieure à l'énergie de collage El de l'interface de détachement privilégié 1. En particulier, l'écart entre l'énergie de collage E2 et l'énergie de collage El est de l'ordre de 1000mJ/m2, voire supérieur. The assembly interface 30 formed at the end of this step a4) has a bonding energy E2 greater than the bonding energy E1 of the privileged detachment interface 1. In particular, the difference between the energy bonding E2 and the bonding energy E1 is of the order of 1000mJ / m 2 , or even greater.
A la suite de l'étape a), dont un mode de réalisation particulier vient d'être décrit, le procédé selon l'invention comprend une étape b) consistant en l'application d'une contrainte mécanique au niveau d'un bord de démontage 100a' de la structure démontable 100 (figure 3e (i) et (ii)). Following step a), a particular embodiment of which has just been described, the method according to the invention comprises a step b) consisting in the application of a mechanical stress at an edge of dismantling 100a 'of the removable structure 100 (FIG. 3e (i) and (ii)).
Le bord de démontage 100a' est localisé au plus proche de la zone d'interruption d'assemblage 31 et la contrainte mécanique est apte à initier une onde de séparation dans l'interface d'assemblage 30 ou dans l'interface de détachement privilégié 1. A titre d'exemple, la contrainte mécanique peut être appliquée par insertion d'un biseau 40 entre les bords des substrats donneur 10 et receveur 20 assemblés. Elle peut alternativement être appliquée par injection d'un fluide liquide ou gazeux entre ces mêmes bords, ou par toute autre technique adaptée. Typiquement, la direction de l'onde de propagation est dans le plan (x,y) et perpendiculaire au bord de démontage 100a' ou à la tangente T au bord de démontage 100a'. The dismantling edge 100a 'is located closest to the assembly interruption zone 31 and the mechanical stress is able to initiate a separation wave in the assembly interface 30 or in the privileged detachment interface 1 For example, mechanical stress can be applied by inserting a bevel 40 between the edges of the assembled donor 10 and recipient 20 substrates. It can alternatively be applied by injection of a liquid or gaseous fluid between these same edges, or by any other suitable technique. Typically, the direction of the propagation wave is in the plane (x, y) and perpendicular to the dismantling edge 100a 'or to the tangent T to the dismantling edge 100a'.
Comme évoqué précédemment, il est habituel qu'une structure démontable 100 présente une zone périphérique d'exclusion, du fait de la géométrie de bord des substrats donneur 10 et receveur 20. A noter que cette zone d'exclusion n'est pas représentée sur les figures 3a à 3g par souci de simplification. Lorsque qu'une contrainte mécanique par exemple par insertion d'un biseau 40 est appliquée, il est possible que l'onde de séparation 41 démarre à l'interface d'assemblage 30, et ce malgré la plus faible tenue mécanique de l'interface de détachement privilégié 1. Ce démarrage de l'onde de séparation 41 dans l'interface d'assemblage 30 est notamment favorisé par la présence de la zone d'exclusion, qui donne directement accès à ladite interface 30. As mentioned above, it is usual for a removable structure 100 to have a peripheral exclusion zone, due to the edge geometry of the donor 10 and recipient 20 substrates. Note that this exclusion zone is not shown on FIGS. 3a to 3g for the sake of simplicity. When a mechanical stress for example by inserting a bevel 40 is applied, it is possible that the separation wave 41 starts at the assembly interface 30, despite the lower mechanical strength of the interface. of privileged detachment 1. This start of the separation wave 41 in the assembly interface 30 is in particular favored by the presence of the exclusion zone, which gives direct access to said interface 30.
Pour cela, le procédé selon l'invention se poursuit par l'étape c), au cours de laquelle, si l'initiation de l'onde de séparation 41 se fait à l'interface d'assemblage 30, une déviation de l'onde de séparation dans l'interface de détachement privilégié 1 s'opère lorsque l'onde de séparation 41 passe au niveau la zone d'interruption d'assemblage 31 (figure 3f (i) et (ii)). En effet, les cavités 31a de la zone d'interruption d'assemblage 31 permettent de modifier le champ de contraintes en tête du front de l'onde de séparation 41, favorisant sa déviation vers l'interface de plus faible énergie, en l'occurrence l'interface de détachement privilégié 1. For this, the method according to the invention continues with step c), during which, if the initiation of the separation wave 41 takes place at the assembly interface 30, a deviation of the Separation wave in the privileged detachment interface 1 occurs when the separation wave 41 passes through the assembly interruption zone 31 (Fig. 3f (i) and (ii)). Indeed, the cavities 31a of the assembly interruption zone 31 make it possible to modify the stress field at the head of the front of the separation wave 41, favoring its deviation towards the interface of lower energy, by the occurrence the privileged detachment interface 1.
Il est avantageux que la contrainte mécanique soit appliquée de sorte que la direction de propagation de l'onde de séparation 41, parallèle à l'axe y sur les figures, soit perpendiculaire à au moins un segment rectiligne d'un pourtour de la (ou des) cavité (s) 31a de la zone d'interruption d'assemblage 31 (figure 4a). It is advantageous that the mechanical stress is applied so that the direction of propagation of the separation wave 41, parallel to the y axis in the figures, is perpendicular to at least one rectilinear segment of a periphery of the (or of) cavity (s) 31a of the assembly interruption zone 31 (FIG. 4a).
Selon un autre mode avantageux, la contrainte mécanique est appliquée de sorte que la direction de propagation de l'onde de séparation 41 soit perpendiculaire à un segment rectiligne d'un pourtour de la cavité 31a qui présente la plus grande dimension latérale. Ce cas peut par exemple se rencontrer lorsque la (ou les) cavité (s) 31a présente (nt) une forme rectangulaire. La dimension la plus grande du rectangle (longueur) sera préférentiellement orientée de manière à être perpendiculaire à la direction de propagation de l'onde de séparation 41. According to another advantageous embodiment, the mechanical stress is applied so that the direction of propagation of the separation wave 41 is perpendicular to a rectilinear segment of a periphery of the cavity 31a which has the largest lateral dimension. This case may for example be encountered when the cavity (s) 31a has (have) a rectangular shape. The the largest dimension of the rectangle (length) will preferably be oriented so as to be perpendicular to the direction of propagation of the separation wave 41.
Comme évoqué précédemment, il est également avantageux, dans le cas d'une cavité 31a présentant une forme triangulaire que le sommet du triangle pointe vers le bord de démontage 100a' ; ou en d'autres termes, il est préférentiel que la base du triangle soit traversée en dernier lieu par l'onde de séparation initiée au niveau du bord de démontage 100a' (figure 4a). As mentioned above, it is also advantageous, in the case of a cavity 31a having a triangular shape that the vertex of the triangle points towards the dismantling edge 100a '; or in other words, it is preferable that the base of the triangle is last crossed by the separation wave initiated at the level of the dismantling edge 100a '(FIG. 4a).
Il est à noter que, lorsque l'onde de séparation 41 est initiée directement dans l'interface de détachement privilégié 1 à l'étape b), le passage de ladite onde au niveau de la zone d'interruption d'assemblage 31 ne modifie pas sa localisation : après la traversée de la zone d'interruption 31, l'onde de séparation 41 continue de se propage à l'interface de détachement privilégié 1. It should be noted that, when the separation wave 41 is initiated directly in the privileged detachment interface 1 in step b), the passage of said wave at the level of the assembly interruption zone 31 does not modify not its location: after crossing the interruption zone 31, the separation wave 41 continues to propagate at the privileged detachment interface 1.
Le procédé de transfert comprend ensuite une étape d) de propagation de l'onde de séparation au niveau de l'interface de détachement privilégié 1, pour aboutir à la séparation totale de la structure démontable 100 (figures 3g (i) et 3g (ii)). The transfer method then comprises a step d) of propagation of the separation wave at the level of the privileged detachment interface 1, to result in the total separation of the removable structure 100 (FIGS. 3g (i) and 3g (ii )).
Une fois déviée dans la bonne interface, l'onde de séparation 41 se propage aisément le long de l'interface de détachement privilégié 1, de moindre tenue mécanique, soit spontanément, la contrainte mécanique appliquée pour initier l'onde de séparation 41 étant suffisante pour propager l'onde de séparation, soit grâce au maintien continu ou intermittent de l'application de la contrainte mécanique. Once deflected into the correct interface, the separation wave 41 easily propagates along the privileged detachment interface 1, of lower mechanical strength, or spontaneously, the mechanical stress applied to initiate the separation wave 41 being sufficient to propagate the separation wave, either by continuously or intermittently maintaining the application of mechanical stress.
La figure 4b montre une photo en vue de dessus, d'une couche utile 3 (en silicium) reportée sur un substrat receveur 20 (en silicium) à partir d'une structure démontable 100 selon l'invention. La photo montre en particulier un zoom autour de la zone d'interruption d'assemblage 31, laquelle est formée dans le substrat receveur 20. On observe la déviation de l'onde de séparation entre l'interface d'assemblage 30 (collage direct de type oxyde Si02 / silicium) en amont de la zone d'interruption d'assemblage 31, et l'interface de détachement privilégié (collage direct de type Si02 / Si02), en aval de la zone d'interruption d'assemblage 31. En aval des cavités 31a, la couche utile 3 est reportée sur le substrat receveur 20. Dans l'exemple de la figure 4b, les huit cavités 31a formant la zone d'interruption d'assemblage 31 sont de forme carrée, de dimensions latérales 500 microns x 500 microns et de profondeur 3 microns. Elles sont situées à environ 3mm du bord. FIG. 4b shows a photo in top view, of a useful layer 3 (in silicon) transferred onto a receiving substrate 20 (in silicon) from a removable structure 100 according to invention. The photo shows in particular a zoom around the assembly interruption zone 31, which is formed in the receiving substrate 20. The deviation of the separation wave between the assembly interface 30 is observed (direct bonding of oxide type SiO 2 / silicon) upstream of the assembly interruption zone 31, and the privileged detachment interface (direct bonding of the SiO 2 / Si02 type), downstream of the assembly interruption zone 31. downstream of the cavities 31a, the useful layer 3 is transferred onto the receiving substrate 20. In the example of FIG. 4b, the eight cavities 31a forming the assembly interruption zone 31 are square in shape, with lateral dimensions of 500 microns. x 500 microns and 3 microns deep. They are located about 3mm from the edge.
Le procédé de transfert appliqué à la structure démontable 100 selon la présente invention permet de dévier efficacement l'onde de séparation 41, de l'interface d'assemblage 30 de la structure démontable 100 vers l'interface de détachement privilégié. Il est ainsi possible de maximiser la surface transférée de la couche utile 3 sur un substrat receveur 20 et de reporter une couche utile 3 de grande qualité. The transfer method applied to the removable structure 100 according to the present invention makes it possible to effectively deflect the separation wave 41, from the assembly interface 30 of the removable structure 100 to the privileged detachment interface. It is thus possible to maximize the surface transferred from the useful layer 3 to a receiving substrate 20 and to transfer a useful layer 3 of high quality.
Bien-sûr, l'invention n'est pas limitée aux modes de réalisation décrits et on peut y apporter des variantes de réalisation sans sortir du cadre de l'invention tel que défini par les revendications . Of course, the invention is not limited to the embodiments described and variant embodiments can be provided without departing from the scope of the invention as defined by the claims.
Bien que les modes de réalisation préférés de la structure démontable 100 décrivent une interface de détachement privilégié 1 basée sur un collage direct par adhésion moléculaire, la présente invention s'applique également à d'autre types de d'interfaces. Par exemple, l'interface de détachement privilégié 1 pourrait être constituée par un plan fragile enterré obtenu par implantation d'espèces légères, ou par formation d'une couche en matériau poreux (par exemple silicium poreux), ou encore par formation de dépôts multicouches dont une interface possède une faible énergie (par exemple comme décrit dans la demande FR3082997). En référence à cette dernière option, on peut par exemple citer un multicouche impliquant une couche d'oxyde de silicium ou de nitrure de silicium, sur une couche d'un métal noble (Au, Pt, Ag...), l'interface entre ces couches présentant une faible énergie interfaciale. Although the preferred embodiments of the removable structure 100 describe a privileged detachment interface 1 based on direct bonding by molecular adhesion, the present invention also applies to other types of interfaces. For example, the privileged detachment interface 1 could be constituted by a buried fragile plane obtained by implantation of light species, or by formation of a layer of porous material (for example porous silicon), or even by formation of multilayer deposits. one interface of which has low energy (for example as described in application FR3082997). With reference to this last option, we can for example cite a multilayer involving a layer of silicon oxide or silicon nitride, on a layer of a noble metal (Au, Pt, Ag, etc.), the interface between these layers exhibiting low interfacial energy.
De manière générale, le présent procédé s'applique dès lors que la structure démontable 100 comporte deux interfaces 1,30 présentant un écart d'énergie interfaciale suffisant, en particulier supérieur ou égale à 1000mJ/m2. In general, the present method applies as soon as the removable structure 100 comprises two interfaces 1.30 exhibiting a sufficient difference in interfacial energy, in particular greater than or equal to 1000 mJ / m 2 .

Claims

REVENDICATIONS
1. Structure démontable (100) utilisée pour le transfert ou la manipulation de couches, comprenant : 1. Demountable structure (100) used for the transfer or handling of layers, comprising:
- au moins deux interfaces, une interface d'assemblage (30) et une interface de détachement privilégié (1), - at least two interfaces, an assembly interface (30) and a privileged detachment interface (1),
- un substrat receveur (20) - a receiving substrate (20)
- un substrat donneur (10) comportant une couche utile (3) à transférer disposée sur un substrat initial (2), l'interface de détachement privilégié (1) étant située entre ladite couche utile (3) et le substrat initial (2), et l'interface d'assemblage (30) étant située entre ladite couche utile (3) et le substrat receveur (20), la structure démontable (100) étant caractérisée en ce que : l'interface d'assemblage (30) présente une zone d'interruption d'assemblage (31) comprenant au moins une cavité (31a) présente dans le substrat receveur (20) ou dans la couche utile (3), dans ce dernier cas, la profondeur de la cavité (31a) étant strictement inférieure à l'épaisseur de la couche utile (3), - a donor substrate (10) comprising a useful layer (3) to be transferred arranged on an initial substrate (2), the privileged detachment interface (1) being located between said useful layer (3) and the initial substrate (2) , and the assembly interface (30) being located between said useful layer (3) and the receiving substrate (20), the removable structure (100) being characterized in that: the assembly interface (30) has an assembly interruption zone (31) comprising at least one cavity (31a) present in the receiving substrate (20) or in the useful layer (3), in the latter case, the depth of the cavity (31a) being strictly less than the thickness of the useful layer (3),
- la zone d'interruption d'assemblage (31) est localisée dans une région périphérique de la structure démontable (100) et permet de modifier un champ de contraintes en tête du front d'une onde de séparation (41) lorsque cette dernière est initiée dans l'interface d'assemblage (30) pour le transfert ou la manipulation de la couche utile (3). - the assembly interruption zone (31) is located in a peripheral region of the removable structure (100) and makes it possible to modify a stress field at the head of the front of a separation wave (41) when the latter is initiated in the assembly interface (30) for the transfer or manipulation of the useful layer (3).
2. Structure démontable (100) selon la revendication précédente, dans laquelle la zone d'interruption d'assemblage (31) est située à moins de 10mm des bords de la structure démontable (100). 2. Removable structure (100) according to the preceding claim, wherein the assembly interruption zone (31) is located less than 10mm from the edges of the removable structure (100).
3. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la zone d'interruption d'assemblage s'étend sur une longueur, le long du pourtour de la structure démontable, inférieure ou égale à 20mm. 3. Removable structure (100) according to one of the preceding claims, wherein the assembly interruption zone extends over a length, along the perimeter of the removable structure, less than or equal to 20mm.
4. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la (au moins une) cavité (31a) présente une profondeur comprise entre 0,5 micron et 50 microns . 4. Removable structure (100) according to one of the preceding claims, wherein the (at least one) cavity (31a) has a depth of between 0.5 microns and 50 microns.
5. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la (au moins une) cavité (31a) présente, dans un plan parallèle à l'interface d'assemblage, un pourtour carré, rectangulaire, triangulaire, trapézoïdal ou arrondi. 5. Removable structure (100) according to one of the preceding claims, wherein the (at least one) cavity (31a) has, in a plane parallel to the assembly interface, a square, rectangular, triangular, trapezoidal periphery. or rounded.
6. Structure démontable (100) selon la revendication précédente, dans laquelle au moins un segment rectiligne du pourtour de la (au moins une) cavité (31a) est parallèle à un bord de démontage (100a') de la structure démontable (100) ou à la tangente (T) à un bord de démontage (100a') de la structure démontable (100). 6. Removable structure (100) according to the preceding claim, wherein at least one rectilinear segment of the periphery of the (at least one) cavity (31a) is parallel to a dismantling edge (100a ') of the removable structure (100) or at the tangent (T) to a dismantling edge (100a ') of the removable structure (100).
7. Structure démontable (100) selon la revendication 5, dans laquelle un segment rectiligne du pourtour de la (au moins une) cavité (31a), qui présente la plus grande dimension latérale, est parallèle à un bord de démontage (100a') de la structure démontable (100) ou à la tangente (T) à un bord de démontage (100a') de la structure démontable (100). 7. A removable structure (100) according to claim 5, wherein a rectilinear segment of the periphery of the (at least one) cavity (31a), which has the largest lateral dimension, is parallel to a dismantling edge (100a '). of the removable structure (100) or at the tangent (T) to a dismantling edge (100a ') of the removable structure (100).
8. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la zone d'interruption d'assemblage (31) comprend une pluralité de cavités (31a) espacées entre elles d'une distance comprise entre 1 micron et 1mm. 8. Removable structure (100) according to one of the preceding claims, wherein the assembly interruption zone (31) comprises a plurality of cavities (31a) spaced apart by a distance between 1 micron and 1mm.
9. Structure démontable (100) selon la revendication précédente, dans laquelle le pourcentage de zones de contact, entre les cavités (31a), de la zone d'interruption d'assemblage (31), est inférieur à 80%, voire inférieur à 50%. 9. Removable structure (100) according to the preceding claim, wherein the percentage of contact areas between the cavities (31a) of the assembly interruption area (31) is less than 80%, or even less than 50%.
10. Structure démontable (100) selon l'une des deux revendications précédentes, dans laquelle les cavités (31a) sont alignées suivant une ligne droite ou suivant une ligne courbe, dont la convexité est orientée vers le centre de la structure démontable (100). 10. Removable structure (100) according to one of the two preceding claims, wherein the cavities (31a) are aligned along a straight line or along a curved line, the convexity of which is oriented towards the center of the removable structure (100). .
11. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la zone d'interruption d'assemblage (31) est positionnée à moins de 8mm des bords de la structure démontable (100), voire à moins de 3mm. 11. Removable structure (100) according to one of the preceding claims, wherein the assembly interruption zone (31) is positioned less than 8mm from the edges of the removable structure (100), or even less than 3mm.
12. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle la couche utile (3) présente une épaisseur comprise entre 200nm et 200 microns . 12. Removable structure (100) according to one of the preceding claims, wherein the useful layer (3) has a thickness between 200nm and 200 microns.
13. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle : 13. Removable structure (100) according to one of the preceding claims, wherein:
- l'interface de détachement privilégié (1) présente une première énergie interfaciale (El), l'interface d'assemblage (30) présente une deuxième énergie interfaciale (E2), l'écart d'énergie interfaciale entre l'interface de détachement privilégié (1) et l'interface d'assemblage (30) est supérieur ou égale à 1000mJ/m2. - the privileged detachment interface (1) has a first interfacial energy (El), the assembly interface (30) has a second interfacial energy (E2), the difference in interfacial energy between the detachment interface privileged (1) and the assembly interface (30) is greater than or equal to 1000 mJ / m 2 .
14. Structure démontable (100) selon l'une des revendications précédentes, dans laquelle l'interface de détachement privilégié (1) est une interface de collage par adhésion moléculaire présentant une première énergie de collage (El), et l'interface d'assemblage (30) est une interface de collage par adhésion moléculaire présentant une deuxième énergie de collage (E2), la première énergie de collage (El) étant inférieure à la deuxième énergie de collage (E2). 14. Removable structure (100) according to one of the preceding claims, wherein the privileged detachment interface (1) is a bonding interface by molecular adhesion having a first bonding energy (El), and the interface of assembly (30) is a bonding interface by molecular adhesion having a second bonding energy (E2), the first bonding energy (El) being less than the second bonding energy (E2).
15. Structure démontable (100) selon la revendication précédente, dans laquelle l'écart d'énergie de collage entre l'interface de détachement privilégié (1) et l'interface d'assemblage (30) est au moins de l'ordre de 100OmJ/m2. 15. Removable structure (100) according to the preceding claim, wherein the difference in bonding energy between the privileged detachment interface (1) and the assembly interface (30) is at least of the order of 100OmJ / m 2 .
16. Procédé de transfert d'une couche utile (3) d'un substrat donneur (10) sur un substrat receveur (20), comprenant les étapes suivantes : a) la fourniture d'une structure démontable (100) selon l'une des revendications précédentes, b) l'application d'une contrainte mécanique au niveau d'un bord de démontage (100a') de la structure démontable (100), ledit bord de démontage (100a') étant localisé au plus proche de la zone d'interruption d'assemblage (31) et la contrainte mécanique étant apte à initier une onde de séparation (41) à l'interface d'assemblage (30) ou à l'interface de détachement privilégié (1), c) si l'initiation de l'onde de séparation (41) s'opère à l'interface d'assemblage (30), la déviation de l'onde de séparation (41) dans l'interface de détachement privilégié (1) lorsque l'onde de séparation (41) passe au niveau de la zone d'interruption d'assemblage (31), d) la propagation de l'onde de séparation (41) à l'interface de détachement privilégié (1), pour aboutir à la séparation totale de la structure démontable (100). 16. A method of transferring a useful layer (3) from a donor substrate (10) to a recipient substrate (20), comprising the following steps: a) providing a removable structure (100) according to one. of the preceding claims, b) the application of a mechanical stress at a dismantling edge (100a ') of the dismountable structure (100), said dismantling edge (100a') being located closest to the zone interruption of assembly (31) and the mechanical stress being able to initiate a separation wave (41) at the assembly interface (30) or at the privileged detachment interface (1), c) if l The initiation of the separation wave (41) takes place at the assembly interface (30), the deflection of the separation wave (41) in the privileged detachment interface (1) when the wave separation (41) passes through the assembly interruption zone (31), d) the propagation of the separation wave (41) at the interface of privileged detachment (1), to result in the total separation of the removable structure (100).
17. Procédé de transfert selon la revendication précédente, dans lequel la contrainte mécanique est appliquée de sorte que la direction de propagation de l'onde de séparation (41) soit perpendiculaire à au moins un segment rectiligne d'un pourtour de la (au moins une) cavité (31a) de la zone d'interruption d'assemblage (31). 17. Transfer method according to the preceding claim, wherein the mechanical stress is applied so that the direction of propagation of the separation wave (41) is perpendicular to at least one rectilinear segment of a periphery of the (at least a) cavity (31a) of the assembly interruption zone (31).
18. Procédé de transfert selon l'une des deux revendications précédentes, dans lequel la contrainte mécanique est appliquée de sorte que la direction de propagation de l'onde de séparation (41) soit perpendiculaire à un segment rectiligne d'un pourtour de la (au moins une) cavité (31a) qui présente la plus grande dimension latérale. 18. Transfer method according to one of the two preceding claims, wherein the mechanical stress is applied so that the direction of propagation of the separation wave (41) is perpendicular to a rectilinear segment of a periphery of the ( at least one) cavity (31a) which has the largest lateral dimension.
19. Procédé de transfert selon l'une des trois revendications précédentes, dans lequel la contrainte mécanique est appliquée par insertion d'un outil en biseau (40) entre les bords du substrat receveur (20) et les bords du substrat donneur (10). 19. Transfer method according to one of the three preceding claims, wherein the mechanical stress is applied by inserting a beveled tool (40) between the edges of the recipient substrate (20) and the edges of the donor substrate (10). .
20. Procédé de transfert selon l'une des quatre revendications précédentes, dans lequel l'étape a) comprend : 20. Transfer method according to one of the four preceding claims, wherein step a) comprises:
- la fourniture du substrat donneur (10) comprenant la couche utile (3) disposée sur le substrat initial (2), l'interface de détachement privilégié (1) étant située entre ladite couche utile (3) et ledit substrat initial (2), - the supply of the donor substrate (10) comprising the useful layer (3) arranged on the initial substrate (2), the privileged detachment interface (1) being located between said useful layer (3) and said initial substrate (2) ,
- la fourniture d'un substrat receveur (20), - the supply of a receiving substrate (20),
- la formation d'au moins une cavité (31a) débouchant au niveau d'une face à assembler (20c) du substrat receveur (20) ou au niveau d'une face à assembler (3c) de la couche utile (3), dans une région périphérique du substrat receveur (20) ou de la couche utile (3), l'assemblage de la couche utile (3) et du substrat receveur (20) au niveau de leurs faces à assembler (3c, 20c) respectives. - the formation of at least one cavity (31a) opening out at the level of a face to be assembled (20c) of the receiving substrate (20) or at a face to be assembled (3c) of the useful layer (3), in a peripheral region of the receiving substrate (20) or of the useful layer (3), the assembly of the useful layer ( 3) and the receiving substrate (20) at their respective faces to be assembled (3c, 20c).
EP21719192.3A 2020-04-01 2021-03-16 Removable structure used for the transfer or manipulation of layers, and method for transfer of a layer using said removable structure Pending EP4128324A1 (en)

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PCT/FR2021/050435 WO2021198576A1 (en) 2020-04-01 2021-03-16 Removable structure used for the transfer or manipulation of layers, and method for transfer of a layer using said removable structure

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WO2023117997A1 (en) * 2021-12-24 2023-06-29 Commissariat A L'energie Atomique Et Aux Energies Alternatives Method for manufacturing disassemblable substrates
FR3131435A1 (en) * 2021-12-24 2023-06-30 Commissariat A L'energie Atomique Et Aux Energies Alternatives Process for the manufacture of removable substrates
FR3132788B1 (en) * 2022-02-14 2024-01-05 Soitec Silicon On Insulator METHOD FOR TRANSFERRING A THIN LAYER TO A SUPPORT SUBSTRATE
FR3135820B1 (en) * 2022-05-18 2024-04-26 Commissariat Energie Atomique Method for transferring a layer from a source substrate to a destination substrate

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FR2748851B1 (en) 1996-05-15 1998-08-07 Commissariat Energie Atomique PROCESS FOR PRODUCING A THIN FILM OF SEMICONDUCTOR MATERIAL
FR2819099B1 (en) * 2000-12-28 2003-09-26 Commissariat Energie Atomique METHOD FOR PRODUCING A STACKED STRUCTURE
FR2823599B1 (en) 2001-04-13 2004-12-17 Commissariat Energie Atomique DEMOMTABLE SUBSTRATE WITH CONTROLLED MECHANICAL HOLDING AND METHOD OF MAKING
FR2823596B1 (en) 2001-04-13 2004-08-20 Commissariat Energie Atomique SUBSTRATE OR DISMOUNTABLE STRUCTURE AND METHOD OF MAKING SAME
JP4839818B2 (en) * 2005-12-16 2011-12-21 信越半導体株式会社 Manufacturing method of bonded substrate
FR2995446A1 (en) 2012-09-07 2014-03-14 Soitec Silicon On Insulator Method for manufacturing structure, involves treating outlying area of localized interfaces, selecting localized sealing of interface, and detecting localized defect formation in layer between interfaces
JP5921473B2 (en) * 2013-03-21 2016-05-24 株式会社東芝 Manufacturing method of semiconductor device
FR3082997B1 (en) 2018-06-22 2020-10-02 Commissariat Energie Atomique METHOD OF TRANSFERRING LAYER (S) OF MATERIAL FROM A FIRST SUBSTRATE TO A SECOND SUBSTRATE

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US20230154755A1 (en) 2023-05-18

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