US20110287604A1 - Methods of forming semiconductor structures comprising direct bonding of substrates - Google Patents
Methods of forming semiconductor structures comprising direct bonding of substrates Download PDFInfo
- Publication number
- US20110287604A1 US20110287604A1 US13/195,605 US201113195605A US2011287604A1 US 20110287604 A1 US20110287604 A1 US 20110287604A1 US 201113195605 A US201113195605 A US 201113195605A US 2011287604 A1 US2011287604 A1 US 2011287604A1
- Authority
- US
- United States
- Prior art keywords
- substrate
- wafer
- microcomponents
- mpa
- mechanical pressure
- 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.)
- Abandoned
Links
Images
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
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/76—Making of isolation regions between components
- H01L21/762—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers
- H01L21/7624—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using semiconductor on insulator [SOI] technology
- H01L21/76251—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using semiconductor on insulator [SOI] technology using bonding techniques
-
- 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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/48—Manufacture or treatment of parts, e.g. containers, prior to assembly of the devices, using processes not provided for in a single one of the subgroups H01L21/06 - H01L21/326
-
- 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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
Definitions
- the present invention relates to the field of producing multilayer semiconductor wafers or substrates produced by transferring at least one layer formed from an initial substrate onto a final substrate, the transferred layer corresponding to a portion of the initial substrate.
- the transferred layer may further comprise all or part of a component or a plurality of microcomponents.
- the present invention relates to the problem of heterogeneous deformations that appear during transfer of a layer from a substrate termed the “donor substrate” onto a final substrate termed the “receiving substrate.”
- Such deformations have been observed in particular with the three-dimensional component integration technique (3-D integration) that requires transfer of one or more layers of microcomponents onto a final support substrate, and also with the transfer of circuits or with the fabrication of back-lit imagers.
- the transferred layer or layers include microcomponents (electronic, optoelectronic, etc.) produced at least partially on an initial substrate, said layers then being stacked on a final substrate that may optionally itself include components.
- each transferred layer must be positioned on the final substrate with high precision in order to come into very strict alignment with the subjacent layer. Further, it may be necessary to carry out treatments on the layer after it has been transferred, for example to form other microcomponents, to uncover the surface of the microcomponents, to produce interconnections, etc.
- FIGS. 1A to 1E illustrate an exemplary embodiment of a three-dimensional structure comprising transfer, onto a final substrate, of a layer of microcomponents formed on an initial substrate, and formation of an additional layer of microcomponents on the exposed face of the initial substrate after bonding.
- FIGS. 1A and 1B illustrate an initial substrate 10 on which a first series of microcomponents 11 is formed.
- the microcomponents 11 are formed by photolithography using a mask that can define pattern formation zones corresponding to the microcomponents 11 to be produced.
- the face of the initial substrate 10 comprising the microcomponents 11 is then brought into intimate contact with one face of a final substrate 20 .
- Bonding between the initial substrate 10 and the final substrate 20 is generally carried out by molecular bonding.
- a buried layer of microcomponents 11 is formed at the bonding interface between substrates 10 and 20 .
- the initial substrate 10 is thinned in order to remove a portion of the material present above the layer of microcomponents 11 .
- a composite structure 30 is thus formed from the final substrate 20 and a layer 10 a corresponding to the remaining portion of the initial substrate 10 .
- the next step in producing the three-dimensional structure consists of forming a second layer of microcomponents 12 1 - 12 9 at the exposed surface of the thinned initial substrate 10 or of carrying out additional technical steps on that exposed surface in alignment with the components included in the layer 10 a (contact points, interconnections, etc.).
- the term “microcomponents” is used in the remainder of this text to define devices or any other patterns resulting from technical steps carried out on or in the layers that must be positioned with precision. Thus, they may be active or passive components, a mere contact point, or interconnections.
- a photolithography mask is used that is similar to that used to form the microcomponents 11 .
- the transferred layers typically include marks both at the microcomponents and at the section forming the layer that are in particular used by the positioning and alignment tools during the technical treatment steps, such as those carried out during photolithography.
- offsets occur between some of the microcomponents 11 1 - 11 9 and 12 1 - 12 9 , such as the offsets ⁇ 11 , ⁇ 22 , ⁇ 33 , ⁇ 44 indicated in FIG. 1E (respectively corresponding to the offsets observed between the pairs of microcomponents 11 1 / 12 1 , 11 2 / 12 2 , 11 3 / 12 3 and 11 4 / 12 4 ).
- Such offsets are not the result of elementary transformations (translation, rotation or combinations thereof) that could originate in inaccurate assembly of the substrates.
- These offsets result from non-homogeneous deformations that appear in the layer derived from the initial substrate while it is being assembled with the final substrate. In fact, such deformations involve local and non-uniform displacements of certain microcomponents 11 .
- certain of the microcomponents 12 1 - 12 9 formed on the exposed surface of the substrate after transfer exhibit positional variations with those microcomponents 11 that may be of the order of several hundred nanometers, or even of micrometer order.
- This phenomenon of misalignment (also termed “overlay”) between the two layers of microcomponents 11 and 12 1 - 12 9 may be a source of short circuits, distortions in the stack, or connection defects between the microcomponents of the two layers.
- overlay also termed “overlay”
- the transferred microcomponents are imagers made up of pixels, and the post-transfer treatment steps are aimed at forming color filters on each of those pixels, a loss of the colorizing function is observed for certain of those pixels.
- the overlay phenomenon thus results in a reduction in the quality and the value of the fabricated multilayer semiconductor wafers.
- the impact of the phenomenon is increasing because of the ever-increasing demand for miniaturization of microcomponents and their increased integration density per layer.
- the invention aims to provide a solution that can limit non-homogenous deformations which appear in a substrate during transfer thereof onto another substrate.
- the present invention proposes a method of initiating molecular bonding, comprising bringing one face of a first wafer or substrate to face one face of a second wafer or substrate and initiating a point of contact between the two facing faces, the method being characterized in that the point of contact is initiated by applying mechanical pressure to one of the two wafers, said pressure being in the range 0,1 MPa [megapascal] to 33.3 MPa.
- the mechanical pressure is applied over a surface area of 1 mm 2 or less.
- initiation of the point of contact is achieved by applying a tool to one of the two substrates, the tool having a contact surface area on the substrate in the range 0.3 mm 2 to 1 mm 2 and in that the bearing force exerted by the tool on the substrate is in the range 0,1 N [newton] to 10 N.
- the present invention also provides a method of producing a composite three-dimensional structure, comprising a step of producing a first layer of microcomponents on one face of a first wafer or substrate and a step of bonding the face of the first wafer comprising the layer of microcomponents onto a second wafer or substrate, the method being characterized in that during the bonding step, molecular bonding is initiated in accordance with the molecular bonding initiation method of the invention.
- the use of a molecular bonding initiation method of the present invention can, during transfer of a layer of microcomponents, eliminate or limit the phenomenon of overlay and produce very high quality multilayer semiconductor wafers.
- the layer of microcomponents may in particular include image sensors.
- FIGS. 1A to 1E are diagrammatic views showing the production of a prior art three-dimensional structure
- FIG. 2 is a diagrammatic view of a molecular bonding initiation method in accordance with one embodiment of the invention
- FIGS. 3A to 3D are diagrammatic views showing the production of a three-dimensional structure using the molecular bonding initiation method of the present invention.
- FIG. 4 is an organigram of the steps carried out during production of the three-dimensional structure shown in FIGS. 3A to 3D ;
- FIGS. 5 to 7 show, highly diagrammatical, implementations of the molecular bonding initiation method of the invention.
- the present invention is generally applicable to the production of composite structures including at least the bonding of a first substrate or wafer onto a second substrate or wafer by molecular bonding.
- Bonding by molecular bonding is a technique that is well known to those skilled in the art. It should be recalled that the principle of bonding by molecular bonding is based on bringing two surfaces into direct contact, i.e., without the use of a specific material (adhesive, wax, brazing material, etc.). Such an operation requires the surfaces for bonding to be sufficiently smooth, to be free of particles or of contamination, and to be sufficiently close together for contact to be initiated, typically a distance of less than a few nanometers. The attractive forces between the two surfaces are then sufficiently high to cause molecular bonding (bonding induced by the set of attractive forces (Van der Waals forces)) of electronic interaction between atoms or molecules of the two surfaces to be bonded.
- Molecular bonding is carried out by initiating a point of contact on one wafer in intimate contact with another wafer in order to trigger the propagation of a bonding wave from that point of contact.
- the tee in “bonding wave” used here is the bonding or molecular bonding front that propagates from the initiation point and that corresponds to diffusion of the attractive forces (Van der Waals forces) from the point of contact over the whole surface area between the two wafers in intimate contact (bonding interface).
- the point of contact is initiated by applying mechanical pressure to one of the two wafers.
- deformations are principally localized at and around the point of contact and that these deformations are elastic. These deformations may extend over a radius of up to 15 cm about the point of pressure application.
- the present invention proposes controlling the mechanical pressure applied at the contact point in order to limit the stresses in this zone while allowing initiation and propagation of a bonding wave between the two wafers in contact.
- the pressure applied at the point of contact is in the range 0,1 MPa to 33.3 MPa.
- the initiation point may be located anywhere on the wafer. It is preferably located close to the edge thereof.
- the surface area of the zone of application of this pressure is typically less than a few mm 2 , for example 1 mm 2 . Larger application surface areas are possible but run the risk that too large a contact surface area (more than 5 mm 2 , for example) could result in aggravation of the deformation (overlay).
- the application of such a mechanical pressure is sufficient to initiate a point of contact between two wafers and as a result to allow the propagation of a bonding wave over the whole contact surface between the wafers without causing stresses that are too high.
- the mechanical pressure applied to initiate the point of contact the deformations arising in the wafer are reduced.
- the pressure applied at the point of contact is less than 10 MPa; more preferably, this pressure is in the range 0,1 MPa to 5 MPa.
- the period during which the mechanical pressure is applied corresponds to at least the minimum period that can activate the phenomenon of propagation of the bonding wave. This minimum period substantially corresponds to the period necessary for the bonding wave to propagate over the contact surface between the wafers.
- the mechanical pressure application period is generally between 1 and 10 seconds, typically 5 seconds, in order to assemble wafers with a 200 mm diameter.
- a first wafer or substrate 60 is placed in a bonding machine comprising a substrate support device 40 .
- the substrate support device 40 comprises a support platen 40 a the planarity defects of which are preferably less than 15 microns.
- the support platen 40 a holds the first wafer 60 , for example by means of an electrostatic or suction system associated with the support platen 40 a or simply under gravity, with a view to assembling it by molecular bonding, with a second wafer or substrate 70 .
- the associated systems for holding the wafer are used provided that it has been ascertained that they do not deform the wafer so as not to accentuate problems with overlay.
- the surfaces 61 and 71 respectively of wafers 60 and 70 that are to be bonded have been prepared (polishing, cleaning, hydrophobic/hydrophilic treatment, etc.) in order to allow molecular bonding.
- the tool 50 comprises a bearing element 51 , such as a stylus, and a dynamometer 53 .
- the bearing element 51 is connected to the dynamometer 53 and comprises a free end 52 via which a mechanical pressure is exerted on the wafer 70 in order to initiate a point of contact between the two wafers 60 and 70 .
- the end 52 has a contact surface area 52 a that is in the range 0.3 mm 2 and 1 mm 2 .
- a mechanical pressure of 3.5 MPa pressure sufficient to initiate a point of contact and, as a result, a bonding wave between the two wafers
- a bearing force of 3.5 N is applied, for instance for about 6 seconds.
- the bearing element and more particularly its end intended to come into contact with the wafer may be produced from or covered with a material such as TEFLON®, silicone or a polymer.
- a material such as TEFLON®, silicone or a polymer.
- the end of the bearing element is produced from or coated with a material that is sufficiently rigid to be able to apply the pressure in a controlled manner. Too flexible a material would deform and result in an imprecise contact surface and as a result in a lack of precision in the applied pressure. In contrast, too rigid a material could result in the formation of defects (impression) on the surface of the wafer.
- the molecular bonding initiation method of the invention may be carried out automatically in a bonding machine.
- the machine then comprises a bearing element connected to an actuator (for example a cylinder or a mechanical arm).
- the machine has the ability to position the bearing element at any location on the surface of the wafer, or along a diameter or a along a radius of the stack formed of the bonded wafers.
- the machine also comprises a force sensor (dynamometer, stress gage, etc.) and a servocontrol intended to drive the actuator. The servocontrol drives the actuator in a manner that controls the mechanical pressure applied by the bearing element.
- the servocontrol receives data from the force sensor and compares them with a predetermined value for the bearing force that is a function of the mechanical pressure that should be applied and of the surface area of the end of the bearing element.
- the machine may also comprise a measurement system to determine the wafers deformation (such as bow and warp measurements). As it will be understood from the discussion below, low pressure to initiate the bonding wave (for instance below 1 MPa), could be achieved if the initiation location is positioned at predetermined specific positions.
- the wafers have limited bow deformation. It may be difficult to initiate, in a repeatable manner, the development of the bonding wave with the limited pressure of the invention (in particular when the pressure is selected so as to be less than 10 MPa, or in the range 0,1 to 5 MPa).
- the acceptable deformation for wafers or substrates in order to ensure good bonding should be in the range ⁇ 10 ⁇ m to +10 ⁇ m for the final substrate or wafer (support substrate) with a 200 mm diameter and in the range ⁇ 45 ⁇ m to +45 ⁇ m for the initial substrate or wafer comprising components (this wafer having a wider range of tolerable deformation since deposition of the oxide or anything of any other nature that is carried out on the components in order to facilitate the molecular bonding step introduces additional deformation).
- a wafer 520 for example a circuit wafer having a concave deformation, must be bonded by molecular bonding onto a planar wafer 510 , for example a bulk wafer that may have been oxidized.
- the point of contact initiated by application of a mechanical pressure Pm is then preferably located at point A, namely at the center of the concave deformation, rather than at point B since the mechanical pressure that has to be applied to initiate bonding would be higher in absolute terms at point B than at point A and as a result would produce greater deformations.
- a test has been carried out with wafers of substrates similar to those illustrated in FIG. 5 . In this test, a force of 0,3 N is applied during about 2 seconds at the center of the generally concave wafer or substrate 520 positioned in contact with the generally flat wafer or substrate 510 . This generally flat wafer or substrate 510 is placed itself on a flat wafer/substrate support device of a bonding machine. In this particular configuration, the limited force is sufficient to initiate the bonding wave while minimizing the wafers deformation.
- the point of contact could also be selected such that it corresponds to a location where the wafer support device and the supported wafer are in close contact or at the shortest distance from one another, in particular when the supported wafer presents at least a concave or convex deformation.
- a wafer 620 for example a circuit wafer
- a wafer 620 has a more complex deformation, i.e., with several concave and convex portions relative to another flat wafer 610
- the point of contact and thus application of the mechanical pressure Pm is initiated at the center of the concave zones of the wafer 620 .
- the center of the concave zones corresponds to the regions of the wafers where the distance between these regions and the flat wafer 610 is the smallest and as a result requires the application of a lower mechanical pressure than at other zones on the wafers.
- the mechanical pressure is applied at a location where the substrate support device is in close proximity of the wafer 610 to avoid any vertical displacement of the bonded stack while the bonding wave is being displaced.
- FIG. 7 two wafers 710 and 720 , respectively, to be assembled and each having their own deformation.
- the choice of the point of application of mechanical pressure Pm to initiate the point of contact between the two wafers is determined as a function of the position of the two wafers when they are placed facing each other.
- Information of the wafers shapes collected from the wafer deformation measurement system could be used to determine the most appropriate location.
- a predetermined deformation may be imposed on one or both wafers so that the zone of the wafer present beneath the tool corresponds to the point requiring the least mechanical pressure.
- a bonding machine in which the tool is in a fixed position above the center of the wafers, it may, for example, be possible to impose on the upper wafer a deformation similar to that of FIG. 5 .
- the process of the invention is applicable to assembling any type of material that is compatible with molecular bonding, in particular semiconductor materials such as silicon, germanium, glass, quartz, sapphire, etc.
- the wafers to be assembled may in particular have a diameter of 100 mm, 150 mm, 200 mm or 300 mm.
- the wafers may also include microcomponents on the majority of their surface or only in a limited zone.
- One particular but non-exclusive field for the assembly method of the present invention is that of producing three-dimensional structures.
- FIGS. 3A to 3D and 4 One method of producing a three-dimensional structure by transfer of a layer of microcomponents formed on an initial substrate onto a final substrate in accordance with an embodiment of the invention is described with reference to FIGS. 3A to 3D and 4 .
- Production of the three-dimensional structure commences by forming a first series of microcomponents 110 on the surface of a wafer or initial substrate 100 ( FIG. 3A , step S 1 ).
- the microcomponents 110 may be entire components and/or only a portion thereof.
- the initial substrate 100 may be a monolayer structure, for example a layer of silicon, or a multilayer structure such as an SOI type structure.
- the microcomponents 110 are formed by photolithography using a mask that can define pattern formation zones corresponding to the microcomponents 110 to be produced.
- the initial substrate 100 is held on a substrate support device 120 .
- the substrate support device comprises a support platen 120 a with which the initial substrate 100 lies flush, for example by means of an electrostatic or suction system associated with the support platen 120 a.
- the face of the initial substrate 100 comprising the microcomponents 110 is then brought into contact with one face of a final wafer or substrate 200 (step S 2 ) with a view to bonding by molecular bonding.
- a layer of oxide, for example of SiO 2 may also be formed on the face of the initial substrate 100 comprising the microcomponents 110 and/or on the face of the final substrate 200 intended to be brought into intimate contact.
- the point of contact is initiated between the two substrates by applying a mechanical pressure Pm on the substrate 200 , preferably close to the edge thereof (step S 3 , FIG. 3B ).
- the pressure Pm is in the range 0,1 MPa to 33.3 MPa and applied to a bearing surface of 1 mm 2 or less.
- Initiation of the point of contact involves propagating a bonding wave on the interface between the initial substrate 100 and the final substrate 200 .
- the two substrates are then bonded together by molecular bonding over the whole of their contact surface (bonding interface), without or almost without deformation in the initial substrate 100 comprising the microcomponents 110 .
- This thereby produces a buried layer of microcomponents 110 at the bonding interface between the substrates 100 and 200 .
- the initial substrate 100 is thinned-down in order to remove a portion of the material present above the layer of microcomponents 110 (step S 4 ).
- the substrate 100 is a SOI type substrate, it is advantageously possible to use the buried insulating layer to define the thickness of the remaining layer 100 a .
- a composite structure 300 is produced, formed from the final substrate 200 and a layer 100 a corresponding to the remaining portion of the initial substrate 100 .
- the initial substrate 100 may in particular be thinned-down by chemical-mechanical polishing (CMP), chemical etching, or by splitting or fracture along a plane of weakness that has been formed in the substrate by atomic implantation.
- CMP chemical-mechanical polishing
- the next step in producing the three-dimensional structure consists of forming a second layer of microcomponents 140 at the exposed surface of the thinned-down initial substrate 100 ( FIG. 3D , step S 5 ).
- the microcomponents 140 may correspond to complementary portions of the microcomponents 110 to form a finished component and/or to distinct components intended to function with the microcomponents 140 .
- a photolithography mask is used that is similar to that employed to form the microcomponents 110 .
- the composite structure 300 formed by the final substrate 200 and the layer 100 a is held on a support platen 130 a of a substrate carrier device 130 that is identical to the device 120 .
- the photolithography mask is then applied to the free surface of the layer 100 a.
- the three-dimensional structure is formed by a stack of layers, each layer having been transferred by the assembly method of the present invention, and each layer being in alignment with the directly adjacent layers.
- the initial substrate 100 can be bonded onto the final substrate without deformation or at least with a reduction in the deformations in such a manner that significant offsets of the microcomponents 110 before and after transfer of the initial substrate 100 onto the final substrate 200 are no longer observed.
- these residual offsets can be limited to values of less than 200 nanometers (nm), or even 100 nm in a homogeneous manner over the whole surface of the wafer.
- the microcomponents 140 even those with very small sizes (for example ⁇ 1 ⁇ m), may thus be formed easily in alignment with the microcomponents 110 , even after transfer of the initial substrate. This, for example, means that the microcomponents present in two layers or those on two distinct faces of a single layer can be interconnected via metal connections, minimizing the risks of poor interconnection.
- the assembly method of the present invention can eliminate the phenomenon of overlay during transfer of one circuit layer onto another layer or onto a support substrate and produce very high quality multilayer semiconductor wafers.
Abstract
The invention relates to a method of initiating molecular bonding, comprising bringing one face of a first wafer to face one face of a second wafer and initiating a point of contact between the two facing faces. The point of contact is initiated by application to one of the two wafers, for example using a bearing element of a tool, of a mechanical pressure in the range 0,1 MPa to 33.3 MPa.
Description
- This application is a continuation of U.S. patent application Ser. No. 12/936,639, filed Nov. 15, 2010, pending, which is a national phase entry under 35 U.S.C. §371 of International Patent Application PCT/EP2009/060250, filed Aug. 6, 2009, published in English as International Patent Publication WO 2010/023082 A1 on Mar. 4, 2010, which claims the benefit under Article 8 of the Patent Cooperation Treaty to French Application Serial No. 08 55767, filed Aug. 28, 2008, the entire disclosure of each of which application is hereby incorporated herein by this reference.
- The present invention relates to the field of producing multilayer semiconductor wafers or substrates produced by transferring at least one layer formed from an initial substrate onto a final substrate, the transferred layer corresponding to a portion of the initial substrate. The transferred layer may further comprise all or part of a component or a plurality of microcomponents.
- More precisely, the present invention relates to the problem of heterogeneous deformations that appear during transfer of a layer from a substrate termed the “donor substrate” onto a final substrate termed the “receiving substrate.” Such deformations have been observed in particular with the three-dimensional component integration technique (3-D integration) that requires transfer of one or more layers of microcomponents onto a final support substrate, and also with the transfer of circuits or with the fabrication of back-lit imagers. The transferred layer or layers include microcomponents (electronic, optoelectronic, etc.) produced at least partially on an initial substrate, said layers then being stacked on a final substrate that may optionally itself include components. Primarily because of the very small size and the large number of microcomponents present on a single layer, each transferred layer must be positioned on the final substrate with high precision in order to come into very strict alignment with the subjacent layer. Further, it may be necessary to carry out treatments on the layer after it has been transferred, for example to form other microcomponents, to uncover the surface of the microcomponents, to produce interconnections, etc.
- However, the applicant has observed that after transfer, there are circumstances when it is very difficult, if not impossible, to form additional microcomponents that are aligned with the microcomponents formed before transfer.
- This misalignment phenomenon is described with reference to
FIGS. 1A to 1E that illustrate an exemplary embodiment of a three-dimensional structure comprising transfer, onto a final substrate, of a layer of microcomponents formed on an initial substrate, and formation of an additional layer of microcomponents on the exposed face of the initial substrate after bonding.FIGS. 1A and 1B illustrate aninitial substrate 10 on which a first series ofmicrocomponents 11 is formed. Themicrocomponents 11 are formed by photolithography using a mask that can define pattern formation zones corresponding to themicrocomponents 11 to be produced. - As can be seen in
FIG. 1C , the face of theinitial substrate 10 comprising themicrocomponents 11 is then brought into intimate contact with one face of afinal substrate 20. Bonding between theinitial substrate 10 and thefinal substrate 20 is generally carried out by molecular bonding. Thus, a buried layer ofmicrocomponents 11 is formed at the bonding interface betweensubstrates FIG. 1D , theinitial substrate 10 is thinned in order to remove a portion of the material present above the layer ofmicrocomponents 11. Acomposite structure 30 is thus formed from thefinal substrate 20 and alayer 10 a corresponding to the remaining portion of theinitial substrate 10. - As can be seen in
FIG. 1E , the next step in producing the three-dimensional structure consists of forming a second layer of microcomponents 12 1-12 9 at the exposed surface of the thinnedinitial substrate 10 or of carrying out additional technical steps on that exposed surface in alignment with the components included in thelayer 10 a (contact points, interconnections, etc.). For the purposes of simplification, the term “microcomponents” is used in the remainder of this text to define devices or any other patterns resulting from technical steps carried out on or in the layers that must be positioned with precision. Thus, they may be active or passive components, a mere contact point, or interconnections. - In order to form the microcomponents 12 1-12 9 in alignment with the buried
microcomponents 11, a photolithography mask is used that is similar to that used to form themicrocomponents 11. The transferred layers, like thelayer 10 a, typically include marks both at the microcomponents and at the section forming the layer that are in particular used by the positioning and alignment tools during the technical treatment steps, such as those carried out during photolithography. - However, even using positioning tools, offsets occur between some of the microcomponents 11 1-11 9 and 12 1-12 9, such as the offsets Δ11, Δ22, Δ33, Δ44 indicated in
FIG. 1E (respectively corresponding to the offsets observed between the pairs ofmicrocomponents 11 1/12 1, 11 2/12 2, 11 3/12 3 and 11 4/12 4). - Such offsets are not the result of elementary transformations (translation, rotation or combinations thereof) that could originate in inaccurate assembly of the substrates. These offsets result from non-homogeneous deformations that appear in the layer derived from the initial substrate while it is being assembled with the final substrate. In fact, such deformations involve local and non-uniform displacements of
certain microcomponents 11. In addition, certain of the microcomponents 12 1-12 9 formed on the exposed surface of the substrate after transfer exhibit positional variations with thosemicrocomponents 11 that may be of the order of several hundred nanometers, or even of micrometer order. - This phenomenon of misalignment (also termed “overlay”) between the two layers of
microcomponents 11 and 12 1-12 9 may be a source of short circuits, distortions in the stack, or connection defects between the microcomponents of the two layers. Thus, when the transferred microcomponents are imagers made up of pixels, and the post-transfer treatment steps are aimed at forming color filters on each of those pixels, a loss of the colorizing function is observed for certain of those pixels. - The overlay phenomenon thus results in a reduction in the quality and the value of the fabricated multilayer semiconductor wafers. The impact of the phenomenon is increasing because of the ever-increasing demand for miniaturization of microcomponents and their increased integration density per layer.
- Problems with alignment during fabrication of three-dimensional structures are well known. The document by Burns et al., “A Wafer-Scale 3-D Circuit Integration Technology,” IEEE Transactions on Electron Devices,
vol 53,No 10, October 2006, describes a method of detecting variations in alignment between bonded substrates. The document by Haisma et al., “Silicon-Wafer Fabrication and (Potential) Applications of Direct-Bonded Silicon,” Philips Journal of Research, vol 49,No 1/2, 1995, emphasize the importance of wafer flatness, in particular during polishing steps, in order to obtain good quality final wafers, i.e., with as few offsets as possible between the microcomponents. However, those documents are concerned only with the problem of positioning the wafers while they are being assembled. As explained above, the applicant has observed that even when the two wafers are perfectly mutually aligned when put into contact (using marks provided for that purpose), non-homogeneous displacements of certain microcomponents occur following initiation of the bonding wave. - The invention aims to provide a solution that can limit non-homogenous deformations which appear in a substrate during transfer thereof onto another substrate.
- To this end, the present invention proposes a method of initiating molecular bonding, comprising bringing one face of a first wafer or substrate to face one face of a second wafer or substrate and initiating a point of contact between the two facing faces, the method being characterized in that the point of contact is initiated by applying mechanical pressure to one of the two wafers, said pressure being in the
range - Thus, by limiting the pressure applied to one of the two substrates during initiation of a point of contact, the non-homogeneous deformations caused in the wafer are reduced, while carrying out bonding by molecular bonding over the whole surface of the two wafers in contact.
- By minimizing thereby the deformations normally caused by application of a point of contact to produce bonding by molecular bonding, the risks of overlay during subsequent formation of the additional layers of microcomponents are substantially reduced.
- In accordance with a first aspect of the invention, the mechanical pressure is applied over a surface area of 1 mm2 or less.
- In accordance with a particular aspect of the invention, initiation of the point of contact is achieved by applying a tool to one of the two substrates, the tool having a contact surface area on the substrate in the range 0.3 mm2 to 1 mm2 and in that the bearing force exerted by the tool on the substrate is in the
range 0,1 N [newton] to 10 N. - The present invention also provides a method of producing a composite three-dimensional structure, comprising a step of producing a first layer of microcomponents on one face of a first wafer or substrate and a step of bonding the face of the first wafer comprising the layer of microcomponents onto a second wafer or substrate, the method being characterized in that during the bonding step, molecular bonding is initiated in accordance with the molecular bonding initiation method of the invention.
- The use of a molecular bonding initiation method of the present invention can, during transfer of a layer of microcomponents, eliminate or limit the phenomenon of overlay and produce very high quality multilayer semiconductor wafers. The layer of microcomponents may in particular include image sensors.
-
FIGS. 1A to 1E are diagrammatic views showing the production of a prior art three-dimensional structure; -
FIG. 2 is a diagrammatic view of a molecular bonding initiation method in accordance with one embodiment of the invention; -
FIGS. 3A to 3D are diagrammatic views showing the production of a three-dimensional structure using the molecular bonding initiation method of the present invention; -
FIG. 4 is an organigram of the steps carried out during production of the three-dimensional structure shown inFIGS. 3A to 3D ; -
FIGS. 5 to 7 show, highly diagrammatical, implementations of the molecular bonding initiation method of the invention. - The present invention is generally applicable to the production of composite structures including at least the bonding of a first substrate or wafer onto a second substrate or wafer by molecular bonding.
- Bonding by molecular bonding is a technique that is well known to those skilled in the art. It should be recalled that the principle of bonding by molecular bonding is based on bringing two surfaces into direct contact, i.e., without the use of a specific material (adhesive, wax, brazing material, etc.). Such an operation requires the surfaces for bonding to be sufficiently smooth, to be free of particles or of contamination, and to be sufficiently close together for contact to be initiated, typically a distance of less than a few nanometers. The attractive forces between the two surfaces are then sufficiently high to cause molecular bonding (bonding induced by the set of attractive forces (Van der Waals forces)) of electronic interaction between atoms or molecules of the two surfaces to be bonded.
- Molecular bonding is carried out by initiating a point of contact on one wafer in intimate contact with another wafer in order to trigger the propagation of a bonding wave from that point of contact. The tee in “bonding wave” used here is the bonding or molecular bonding front that propagates from the initiation point and that corresponds to diffusion of the attractive forces (Van der Waals forces) from the point of contact over the whole surface area between the two wafers in intimate contact (bonding interface). The point of contact is initiated by applying mechanical pressure to one of the two wafers.
- The applicant has demonstrated that the relative displacements between certain patterns or microcomponents in one and the same wafer appear as a result of the step of molecular bonding of that wafer onto another. More precisely, experiments carried out by the applicant have demonstrated that stresses (tensile and/or compressive) are produced at the point of contact, i.e., the region where the mechanical pressure is applied. These stresses are the source of the non-homogeneous deformations appearing in the wafer and as a result of the relative and unequal displacements of certain patterns or microcomponents relative to each other.
- The applicant has observed that the deformations are principally localized at and around the point of contact and that these deformations are elastic. These deformations may extend over a radius of up to 15 cm about the point of pressure application.
- As a result, the present invention proposes controlling the mechanical pressure applied at the contact point in order to limit the stresses in this zone while allowing initiation and propagation of a bonding wave between the two wafers in contact. In accordance with the invention, the pressure applied at the point of contact is in the
range - The application of such a mechanical pressure is sufficient to initiate a point of contact between two wafers and as a result to allow the propagation of a bonding wave over the whole contact surface between the wafers without causing stresses that are too high. Thus, by controlling the mechanical pressure applied to initiate the point of contact, the deformations arising in the wafer are reduced. Preferably, the pressure applied at the point of contact is less than 10 MPa; more preferably, this pressure is in the
range - The period during which the mechanical pressure is applied corresponds to at least the minimum period that can activate the phenomenon of propagation of the bonding wave. This minimum period substantially corresponds to the period necessary for the bonding wave to propagate over the contact surface between the wafers. The mechanical pressure application period is generally between 1 and 10 seconds, typically 5 seconds, in order to assemble wafers with a 200 mm diameter.
- The controlled application of mechanical pressure may be carried out using a tool. In
FIG. 2 , a first wafer orsubstrate 60 is placed in a bonding machine comprising a substrate support device 40. The substrate support device 40 comprises asupport platen 40 a the planarity defects of which are preferably less than 15 microns. The support platen 40 a holds thefirst wafer 60, for example by means of an electrostatic or suction system associated with thesupport platen 40 a or simply under gravity, with a view to assembling it by molecular bonding, with a second wafer orsubstrate 70. The associated systems for holding the wafer (electrostatic or by suction) are used provided that it has been ascertained that they do not deform the wafer so as not to accentuate problems with overlay. - As explained above and in known manner, the
surfaces wafers - The
surfaces wafers tool 50. As shown in a highly diagrammatic manner inFIG. 2 , thetool 50 comprises a bearingelement 51, such as a stylus, and adynamometer 53. The bearingelement 51 is connected to thedynamometer 53 and comprises afree end 52 via which a mechanical pressure is exerted on thewafer 70 in order to initiate a point of contact between the twowafers end 52 has acontact surface area 52 a that is in the range 0.3 mm2 and 1 mm2. Knowing the area of thecontact surface 52 a of thetool 50 with thewafer 70, it is possible to apply a mechanical pressure in therange end 52 on thewafer 70 is controlled by thedynamometer 53. This force is in therange 0,1 N to 10 N. - As an example, if a mechanical pressure of 3.5 MPa (pressure sufficient to initiate a point of contact and, as a result, a bonding wave between the two wafers) is to be applied with a tool the end of which has a contact surface area of 1 mm2, a bearing force of 3.5 N is applied, for instance for about 6 seconds.
- The bearing element, and more particularly its end intended to come into contact with the wafer may be produced from or covered with a material such as TEFLON®, silicone or a polymer. In general, the end of the bearing element is produced from or coated with a material that is sufficiently rigid to be able to apply the pressure in a controlled manner. Too flexible a material would deform and result in an imprecise contact surface and as a result in a lack of precision in the applied pressure. In contrast, too rigid a material could result in the formation of defects (impression) on the surface of the wafer.
- The molecular bonding initiation method of the invention may be carried out automatically in a bonding machine. The machine then comprises a bearing element connected to an actuator (for example a cylinder or a mechanical arm). In some embodiments, the machine has the ability to position the bearing element at any location on the surface of the wafer, or along a diameter or a along a radius of the stack formed of the bonded wafers. The machine also comprises a force sensor (dynamometer, stress gage, etc.) and a servocontrol intended to drive the actuator. The servocontrol drives the actuator in a manner that controls the mechanical pressure applied by the bearing element. More precisely, the servocontrol receives data from the force sensor and compares them with a predetermined value for the bearing force that is a function of the mechanical pressure that should be applied and of the surface area of the end of the bearing element. The machine may also comprise a measurement system to determine the wafers deformation (such as bow and warp measurements). As it will be understood from the discussion below, low pressure to initiate the bonding wave (for instance below 1 MPa), could be achieved if the initiation location is positioned at predetermined specific positions.
- Preferably, the wafers have limited bow deformation. It may be difficult to initiate, in a repeatable manner, the development of the bonding wave with the limited pressure of the invention (in particular when the pressure is selected so as to be less than 10 MPa, or in the
range - When one or both of the wafers carries a deformation, it may be advantageous to select the location at which the point of contact (place of application of the mechanical pressure) is initiated as a function of the shape of the wafers that are brought into contact in order to further minimize the mechanical pressure necessary for molecular bonding. If the two wafers to be bonded are not perfectly planar, the local mutual separation of the surfaces of the facing wafers will not be constant. Thus, as shown in a highly diagrammatic manner in
FIG. 5 , awafer 520, for example a circuit wafer having a concave deformation, must be bonded by molecular bonding onto aplanar wafer 510, for example a bulk wafer that may have been oxidized. The point of contact initiated by application of a mechanical pressure Pm is then preferably located at point A, namely at the center of the concave deformation, rather than at point B since the mechanical pressure that has to be applied to initiate bonding would be higher in absolute terms at point B than at point A and as a result would produce greater deformations. A test has been carried out with wafers of substrates similar to those illustrated inFIG. 5 . In this test, a force of 0,3 N is applied during about 2 seconds at the center of the generally concave wafer orsubstrate 520 positioned in contact with the generally flat wafer orsubstrate 510. This generally flat wafer orsubstrate 510 is placed itself on a flat wafer/substrate support device of a bonding machine. In this particular configuration, the limited force is sufficient to initiate the bonding wave while minimizing the wafers deformation. - The point of contact could also be selected such that it corresponds to a location where the wafer support device and the supported wafer are in close contact or at the shortest distance from one another, in particular when the supported wafer presents at least a concave or convex deformation.
- These last two requirements insure that the necessary pressure that is applied to initiate the bonding will lead to a minimal vertical displacement of the wafers and thus to minimize wafer deformation.
- Similarly, as shown in
FIG. 6 , when awafer 620, for example a circuit wafer, has a more complex deformation, i.e., with several concave and convex portions relative to anotherflat wafer 610, then preferably the point of contact and thus application of the mechanical pressure Pm is initiated at the center of the concave zones of thewafer 620. The center of the concave zones corresponds to the regions of the wafers where the distance between these regions and theflat wafer 610 is the smallest and as a result requires the application of a lower mechanical pressure than at other zones on the wafers. And preferably, the mechanical pressure is applied at a location where the substrate support device is in close proximity of thewafer 610 to avoid any vertical displacement of the bonded stack while the bonding wave is being displaced. - In
FIG. 7 , twowafers - Information of the wafers shapes collected from the wafer deformation measurement system could be used to determine the most appropriate location.
- In a variation, for example where a tool (stylus) used to initiate the point of contact cannot be displaced relative to the wafers, a predetermined deformation may be imposed on one or both wafers so that the zone of the wafer present beneath the tool corresponds to the point requiring the least mechanical pressure. Under such circumstances, with a bonding machine in which the tool is in a fixed position above the center of the wafers, it may, for example, be possible to impose on the upper wafer a deformation similar to that of
FIG. 5 . - The process of the invention is applicable to assembling any type of material that is compatible with molecular bonding, in particular semiconductor materials such as silicon, germanium, glass, quartz, sapphire, etc. The wafers to be assembled may in particular have a diameter of 100 mm, 150 mm, 200 mm or 300 mm. The wafers may also include microcomponents on the majority of their surface or only in a limited zone.
- One particular but non-exclusive field for the assembly method of the present invention is that of producing three-dimensional structures.
- One method of producing a three-dimensional structure by transfer of a layer of microcomponents formed on an initial substrate onto a final substrate in accordance with an embodiment of the invention is described with reference to
FIGS. 3A to 3D and 4. - Production of the three-dimensional structure commences by forming a first series of
microcomponents 110 on the surface of a wafer or initial substrate 100 (FIG. 3A , step S1). Themicrocomponents 110 may be entire components and/or only a portion thereof. Theinitial substrate 100 may be a monolayer structure, for example a layer of silicon, or a multilayer structure such as an SOI type structure. Themicrocomponents 110 are formed by photolithography using a mask that can define pattern formation zones corresponding to themicrocomponents 110 to be produced. During the formation ofmicrocomponents 110 by photolithography, theinitial substrate 100 is held on asubstrate support device 120. The substrate support device comprises asupport platen 120 a with which theinitial substrate 100 lies flush, for example by means of an electrostatic or suction system associated with thesupport platen 120 a. - The face of the
initial substrate 100 comprising themicrocomponents 110 is then brought into contact with one face of a final wafer or substrate 200 (step S2) with a view to bonding by molecular bonding. A layer of oxide, for example of SiO2, may also be formed on the face of theinitial substrate 100 comprising themicrocomponents 110 and/or on the face of thefinal substrate 200 intended to be brought into intimate contact. - In accordance with the invention, the point of contact is initiated between the two substrates by applying a mechanical pressure Pm on the
substrate 200, preferably close to the edge thereof (step S3,FIG. 3B ). As indicated above, the pressure Pm is in therange - Initiation of the point of contact involves propagating a bonding wave on the interface between the
initial substrate 100 and thefinal substrate 200. The two substrates are then bonded together by molecular bonding over the whole of their contact surface (bonding interface), without or almost without deformation in theinitial substrate 100 comprising themicrocomponents 110. This thereby produces a buried layer ofmicrocomponents 110 at the bonding interface between thesubstrates - After bonding and as can be seen in
FIG. 3C , theinitial substrate 100 is thinned-down in order to remove a portion of the material present above the layer of microcomponents 110 (step S4). When thesubstrate 100 is a SOI type substrate, it is advantageously possible to use the buried insulating layer to define the thickness of the remaininglayer 100 a. Thus, acomposite structure 300 is produced, formed from thefinal substrate 200 and alayer 100 a corresponding to the remaining portion of theinitial substrate 100. Theinitial substrate 100 may in particular be thinned-down by chemical-mechanical polishing (CMP), chemical etching, or by splitting or fracture along a plane of weakness that has been formed in the substrate by atomic implantation. - As can be seen in
FIG. 3D , the next step in producing the three-dimensional structure consists of forming a second layer ofmicrocomponents 140 at the exposed surface of the thinned-down initial substrate 100 (FIG. 3D , step S5). Themicrocomponents 140 may correspond to complementary portions of themicrocomponents 110 to form a finished component and/or to distinct components intended to function with themicrocomponents 140. In order to form themicrocomponents 140 in alignment with the buriedmicrocomponents 110, a photolithography mask is used that is similar to that employed to form themicrocomponents 110. As during formation of themicrocomponents 110, thecomposite structure 300 formed by thefinal substrate 200 and thelayer 100 a is held on asupport platen 130 a of asubstrate carrier device 130 that is identical to thedevice 120. The photolithography mask is then applied to the free surface of thelayer 100 a. - In a variation, the three-dimensional structure is formed by a stack of layers, each layer having been transferred by the assembly method of the present invention, and each layer being in alignment with the directly adjacent layers.
- By using the molecular bonding initiation method of the invention, the
initial substrate 100 can be bonded onto the final substrate without deformation or at least with a reduction in the deformations in such a manner that significant offsets of themicrocomponents 110 before and after transfer of theinitial substrate 100 onto thefinal substrate 200 are no longer observed. Thus, these residual offsets can be limited to values of less than 200 nanometers (nm), or even 100 nm in a homogeneous manner over the whole surface of the wafer. Themicrocomponents 140, even those with very small sizes (for example <1 μm), may thus be formed easily in alignment with themicrocomponents 110, even after transfer of the initial substrate. This, for example, means that the microcomponents present in two layers or those on two distinct faces of a single layer can be interconnected via metal connections, minimizing the risks of poor interconnection. - As a result, the assembly method of the present invention can eliminate the phenomenon of overlay during transfer of one circuit layer onto another layer or onto a support substrate and produce very high quality multilayer semiconductor wafers.
Claims (27)
1. A method of forming a three-dimensionally integrated structure, comprising:
directly contacting a surface of a first substrate with a surface of a second substrate;
applying mechanical pressure in a range extending from 0.1 MPa to 33.3 MPa to at least one of the first substrate and the second substrate; and
initiating and propagating a bonding wave across an interface between the surface of a first substrate and the surface of the second substrate resulting in the formation of a direct inter-atomic bonds between the surface of the first substrate and the surface of the second substrate.
2. The method of claim 1 , wherein applying mechanical pressure in a range extending from 0.1 MPa to 33.3 MPa to at least one of the first substrate and the second substrate comprises applying mechanical pressure in a range extending from 0.1 MPa to 10 MPa to at least one of the first substrate and the second substrate.
3. The method of claim 2 , wherein applying mechanical pressure in a range extending from 0.1 MPa to 10 MPa to at least one of the first substrate and the second substrate comprises applying mechanical pressure in a range extending from 2 MPa to 5 MPa to at least one of the first substrate and the second substrate.
4. The method of claim 1 , wherein applying mechanical pressure comprises applying the mechanical pressure over a contact surface area of 5 mm2 or less.
5. The method of claim 4 , further comprising applying the mechanical pressure over a contact surface area of 1 mm2 or less.
6. The method of claim 5 , further comprising applying the mechanical pressure over a contact area in a range extending from 0.3 mm2 to 1 mm2 between a tool and a surface of the at least one of the first substrate and the second substrate, and exerting a bearing force in a range extending from 0.1 N to 10 N on the surface of the of the at least one of the first substrate and the second substrate by the tool.
7. The method of claim 6 , further comprising providing a polymer material on at least an end of the tool intended to bear on the surface of the at least one of the first substrate and the second substrate.
8. The method of claim 1 , further comprising providing an oxide material on at least one of the surface of the first substrate and the surface of the second substrate prior to directly contacting the surface of the first substrate with the surface of the second substrate.
9. The method of claim 1 , further comprising forming a first plurality of microcomponents on the surface of the first substrate prior to directly contacting the surface of the first substrate with the surface of the second substrate.
10. The method of claim 9 , further comprising forming a second plurality of microcomponents on an exposed surface of the second substrate after formation of the direct inter-atomic bonds between the surface of the first substrate and the surface of the second substrate.
11. The method of claim 10 , further comprising vertically aligning at least some microcomponents of the second plurality of microcomponents with at least some of the first plurality of microcomponents and limiting unintended horizontal offsets between the vertically aligned microcomponents of the first and second pluralities of microcomponents to values less than 200 nm.
12. The method of claim 11 , further comprising limiting the unintended horizontal offsets between the vertically aligned microcomponents of the first and second pluralities of microcomponents to values less than 100 nm.
13. The method of claim 10 , further comprising limiting the unintended horizontal offsets between the vertically aligned microcomponents of the first and second pluralities of microcomponents to values less than 200 nm in a homogenous manner over the entire three-dimensionally integrated structure.
14. The method of claim 10 , further comprising forming at least some microcomponents of the first plurality of microcomponents to comprise image sensors.
15. The method of claim 14 , further comprising forming at least some microcomponents of the second plurality of microcomponents to comprise color filters.
16. The method of claim 10 , further comprising forming at least some microcomponents of the second plurality of microcomponents to comprise at least one of contact points and interconnections.
17. The method of claim 1 , further comprising selecting the first substrate to comprise an SOI structure.
18. A method of forming a semiconductor structure, comprising:
directly contacting a surface of a first wafer with a surface of a second wafer;
applying mechanical pressure in a range extending from 0.1 MPa to 33.3 MPa to at least one of the first wafer and the second wafer; and
establishing a direct bond between the surface of the first wafer and the surface of the second wafer, the direct bond resulting from atomic interactions at the interface between the surface of the first wafer and the surface of the second wafer.
19. The method of claim 18 , wherein establishing a direct bond between the surface of the first wafer and the surface of the second wafer comprises initiating and propagating a bonding wave across an interface between the surface of a first wafer and the surface of the second wafer.
20. The method of claim 19 , wherein applying mechanical pressure in a range extending from 0.1 MPa to 33.3 MPa to at least one of the first wafer and the second wafer comprises applying mechanical pressure in a range extending from 0.1 MPa to 10 MPa to at least one of the first wafer and the second wafer.
21. The method of claim 20 , wherein applying mechanical pressure in a range extending from 0.1 MPa to 10 MPa to at least one of the first wafer and the second wafer comprises applying mechanical pressure in a range extending from 2 MPa to 5 MPa to at least one of the first wafer and the second wafer.
22. The method of claim 18 , wherein applying mechanical pressure comprises applying the mechanical pressure over a contact surface area of 5 mm2 or less.
23. The method of claim 22 , further comprising applying the mechanical pressure over a contact surface area of 1 mm2 or less.
24. The method of claim 23 , further comprising applying the mechanical pressure over a contact area in a range extending from 0.3 mm2 to 1 mm2 between a tool and the at least one of the first wafer and the second wafer, and exerting a bearing force in a range extending from 0.1 N to 10 N on the at least one of the first wafer and the second wafer by the tool.
25. The method of claim 18 , further comprising forming a first plurality of microcomponents on the surface of the first wafer prior to directly contacting the surface of the first wafer with the surface of the second wafer.
26. The method of claim 25 , further comprising forming a second plurality of microcomponents on an exposed surface of the second wafer after establishing the direct bond between the surface of the first wafer and the surface of the second wafer.
27. The method of claim 26 , further comprising vertically aligning at least some microcomponents of the second plurality of microcomponents with at least some of the first plurality of microcomponents and limiting unintended horizontal offsets between the vertically aligned microcomponents of the first and second pluralities of microcomponents to values less than 200 nm.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/195,605 US20110287604A1 (en) | 2008-08-28 | 2011-08-01 | Methods of forming semiconductor structures comprising direct bonding of substrates |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0855767A FR2935537B1 (en) | 2008-08-28 | 2008-08-28 | MOLECULAR ADHESION INITIATION METHOD |
FR0855767 | 2008-08-28 | ||
PCT/EP2009/060250 WO2010023082A1 (en) | 2008-08-28 | 2009-08-06 | A method of initiating molecular bonding |
US93663910A | 2010-11-15 | 2010-11-15 | |
US13/195,605 US20110287604A1 (en) | 2008-08-28 | 2011-08-01 | Methods of forming semiconductor structures comprising direct bonding of substrates |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2009/060250 Continuation WO2010023082A1 (en) | 2008-08-21 | 2009-08-06 | A method of initiating molecular bonding |
US93663910A Continuation | 2008-08-21 | 2010-11-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110287604A1 true US20110287604A1 (en) | 2011-11-24 |
Family
ID=40361570
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/936,639 Expired - Fee Related US8163570B2 (en) | 2008-08-28 | 2009-08-06 | Method of initiating molecular bonding |
US13/195,583 Abandoned US20130093033A9 (en) | 2008-08-21 | 2011-08-01 | Three dimensional structures having improved alignments between layers of microcomponents |
US13/195,605 Abandoned US20110287604A1 (en) | 2008-08-28 | 2011-08-01 | Methods of forming semiconductor structures comprising direct bonding of substrates |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/936,639 Expired - Fee Related US8163570B2 (en) | 2008-08-28 | 2009-08-06 | Method of initiating molecular bonding |
US13/195,583 Abandoned US20130093033A9 (en) | 2008-08-21 | 2011-08-01 | Three dimensional structures having improved alignments between layers of microcomponents |
Country Status (8)
Country | Link |
---|---|
US (3) | US8163570B2 (en) |
EP (1) | EP2319074A1 (en) |
JP (1) | JP2011524084A (en) |
KR (3) | KR20100139023A (en) |
CN (1) | CN102017125A (en) |
FR (1) | FR2935537B1 (en) |
TW (1) | TW201017739A (en) |
WO (1) | WO2010023082A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014001868A1 (en) * | 2012-06-28 | 2014-01-03 | Soitec | Method for producing composite structure with metal/metal bonding |
US8927320B2 (en) | 2009-06-26 | 2015-01-06 | Soitec | Method of bonding by molecular bonding |
US8932938B2 (en) | 2009-03-12 | 2015-01-13 | Soitec | Method of fabricating a multilayer structure with circuit layer transfer |
US20150044786A1 (en) * | 2013-08-09 | 2015-02-12 | Taiwan Semiconductor Manufacturing Company, Ltd. | Alignment Systems and Wafer Bonding Systems and Methods |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8459128B2 (en) * | 2008-04-15 | 2013-06-11 | Indian Institute Of Science | Sub-threshold elastic deflection FET sensor for sensing pressure/force, a method and system thereof |
FR2935537B1 (en) | 2008-08-28 | 2010-10-22 | Soitec Silicon On Insulator | MOLECULAR ADHESION INITIATION METHOD |
FR2935536B1 (en) * | 2008-09-02 | 2010-09-24 | Soitec Silicon On Insulator | PROGRESSIVE DETOURING METHOD |
EP2200077B1 (en) * | 2008-12-22 | 2012-12-05 | Soitec | Method for bonding two substrates |
US8314487B2 (en) * | 2009-12-18 | 2012-11-20 | Infineon Technologies Ag | Flange for semiconductor die |
FR2961630B1 (en) | 2010-06-22 | 2013-03-29 | Soitec Silicon On Insulator Technologies | APPARATUS FOR MANUFACTURING SEMICONDUCTOR DEVICES |
US8338266B2 (en) | 2010-08-11 | 2012-12-25 | Soitec | Method for molecular adhesion bonding at low pressure |
FR2963848B1 (en) * | 2010-08-11 | 2012-08-31 | Soitec Silicon On Insulator | LOW PRESSURE MOLECULAR ADHESION COLLAGE PROCESS |
FR2964193A1 (en) | 2010-08-24 | 2012-03-02 | Soitec Silicon On Insulator | METHOD FOR MEASURING ADHESION ENERGY, AND ASSOCIATED SUBSTRATES |
US8673733B2 (en) | 2011-09-27 | 2014-03-18 | Soitec | Methods of transferring layers of material in 3D integration processes and related structures and devices |
TWI573198B (en) | 2011-09-27 | 2017-03-01 | 索泰克公司 | Methods of transferring layers of material in 3d integration processes and related structures and devices |
US8841742B2 (en) | 2011-09-27 | 2014-09-23 | Soitec | Low temperature layer transfer process using donor structure with material in recesses in transfer layer, semiconductor structures fabricated using such methods |
US9245836B2 (en) | 2012-06-28 | 2016-01-26 | Soitec | Interposers including fluidic microchannels and related structures and methods |
TWI602315B (en) | 2013-03-08 | 2017-10-11 | 索泰克公司 | Photoactive devices having low bandgap active layers configured for improved efficiency and related methods |
US9698035B2 (en) * | 2013-12-23 | 2017-07-04 | Lam Research Corporation | Microstructures for improved wafer handling |
JP6550741B2 (en) * | 2014-12-17 | 2019-07-31 | 富士電機株式会社 | Manufacturing method of semiconductor device |
US20160204078A1 (en) * | 2015-01-14 | 2016-07-14 | International Business Machines Corporation | Bonding process using temperature controlled curvature change |
CN105957817A (en) * | 2016-07-12 | 2016-09-21 | 武汉新芯集成电路制造有限公司 | Wafer bonding method |
JP7137571B2 (en) * | 2017-03-02 | 2022-09-14 | エーファウ・グループ・エー・タルナー・ゲーエムベーハー | Method and apparatus for bonding chips |
US10720345B1 (en) * | 2017-09-15 | 2020-07-21 | Intel Corporation | Wafer to wafer bonding with low wafer distortion |
TWI668739B (en) * | 2018-04-03 | 2019-08-11 | 環球晶圓股份有限公司 | Epitaxy substrate and method of manufacturing the same |
CN109103079B (en) * | 2018-08-06 | 2021-06-01 | 济南晶正电子科技有限公司 | Nanoscale single crystal film and preparation method thereof |
US11829077B2 (en) | 2020-12-11 | 2023-11-28 | Kla Corporation | System and method for determining post bonding overlay |
US11782411B2 (en) | 2021-07-28 | 2023-10-10 | Kla Corporation | System and method for mitigating overlay distortion patterns caused by a wafer bonding tool |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5959957A (en) * | 1996-01-19 | 1999-09-28 | Canon Kabushiki Kaisha | Probe and a cantilever formed with same material |
US20060043512A1 (en) * | 2004-08-24 | 2006-03-02 | Oliver Steven D | Microelectronic imagers with optical devices having integral reference features and methods for manufacturing such microelectronic imagers |
US20090280595A1 (en) * | 2008-05-06 | 2009-11-12 | S.O.I. Tec Silicon On Insulator Technologies | Process for assembling wafers by means of molecular adhesion |
Family Cites Families (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3728694A (en) * | 1970-09-28 | 1973-04-17 | Technovation | Thin film ferroelectric device |
JPH0355822A (en) * | 1989-07-25 | 1991-03-11 | Shin Etsu Handotai Co Ltd | Manufacture of substrate for forming semiconductor element |
JP3321882B2 (en) * | 1993-02-28 | 2002-09-09 | ソニー株式会社 | Substrate bonding method |
US5962792A (en) * | 1997-06-02 | 1999-10-05 | The Penn State Research Foundation | Beam strain gauge |
US6335263B1 (en) * | 2000-03-22 | 2002-01-01 | The Regents Of The University Of California | Method of forming a low temperature metal bond for use in the transfer of bulk and thin film materials |
JP4698018B2 (en) * | 2000-12-12 | 2011-06-08 | 日本碍子株式会社 | Adhesive manufacturing method and adhesive |
US20020127821A1 (en) * | 2000-12-28 | 2002-09-12 | Kazuyuki Ohya | Process for the production of thinned wafer |
FR2821697B1 (en) | 2001-03-02 | 2004-06-25 | Commissariat Energie Atomique | METHOD OF MANUFACTURING THIN LAYERS ON A SPECIFIC CARRIER AND AN APPLICATION |
FR2837620B1 (en) * | 2002-03-25 | 2005-04-29 | Commissariat Energie Atomique | METHOD FOR TRANSFERRING SUBSTRATE SUBSTRATE ELEMENTS |
US6969667B2 (en) * | 2002-04-01 | 2005-11-29 | Hewlett-Packard Development Company, L.P. | Electrical device and method of making |
CN100359653C (en) * | 2002-04-15 | 2008-01-02 | 肖特股份公司 | Method for connecting substrates and composite element |
EP2273555A3 (en) * | 2002-09-17 | 2012-09-12 | Anteryon B.V. | Camera device |
JP2004235465A (en) * | 2003-01-30 | 2004-08-19 | Tokyo Electron Ltd | Bonding method, bonding device and sealant |
US20040262772A1 (en) * | 2003-06-30 | 2004-12-30 | Shriram Ramanathan | Methods for bonding wafers using a metal interlayer |
WO2005061227A1 (en) * | 2003-12-24 | 2005-07-07 | Teijin Limited | Multilayer body |
FR2866982B1 (en) | 2004-02-27 | 2008-05-09 | Soitec Silicon On Insulator | METHOD FOR MANUFACTURING ELECTRONIC COMPONENTS |
US7645635B2 (en) * | 2004-08-16 | 2010-01-12 | Micron Technology, Inc. | Frame structure and semiconductor attach process for use therewith for fabrication of image sensor packages and the like, and resulting packages |
US7060592B2 (en) * | 2004-09-15 | 2006-06-13 | United Microelectronics Corp. | Image sensor and fabricating method thereof |
WO2006078631A2 (en) | 2005-01-18 | 2006-07-27 | Suss Micro Tec Inc. | High-throughput bond tool |
TWI310583B (en) * | 2005-07-01 | 2009-06-01 | Touch Micro System Tech | Method of thinning a wafer |
JP5046366B2 (en) * | 2005-10-20 | 2012-10-10 | 信越化学工業株式会社 | Adhesive composition and sheet provided with an adhesive layer comprising the adhesive |
US7648851B2 (en) | 2006-03-06 | 2010-01-19 | Taiwan Semiconductor Manufacturing Company, Ltd. | Method of fabricating backside illuminated image sensor |
JP4458116B2 (en) * | 2007-05-30 | 2010-04-28 | 住友電気工業株式会社 | Group III nitride semiconductor layer bonded substrate for epitaxial layer growth and semiconductor device |
JP4442671B2 (en) * | 2007-09-21 | 2010-03-31 | セイコーエプソン株式会社 | Substrate with bonding film, bonding method and bonded body |
FR2935537B1 (en) | 2008-08-28 | 2010-10-22 | Soitec Silicon On Insulator | MOLECULAR ADHESION INITIATION METHOD |
-
2008
- 2008-08-28 FR FR0855767A patent/FR2935537B1/en not_active Expired - Fee Related
-
2009
- 2009-08-06 EP EP09809307A patent/EP2319074A1/en not_active Withdrawn
- 2009-08-06 KR KR1020107023019A patent/KR20100139023A/en active Search and Examination
- 2009-08-06 CN CN2009801152329A patent/CN102017125A/en active Pending
- 2009-08-06 JP JP2011511038A patent/JP2011524084A/en active Pending
- 2009-08-06 WO PCT/EP2009/060250 patent/WO2010023082A1/en active Application Filing
- 2009-08-06 US US12/936,639 patent/US8163570B2/en not_active Expired - Fee Related
- 2009-08-06 KR KR1020127011092A patent/KR20120089695A/en not_active Application Discontinuation
- 2009-08-06 KR KR1020127011093A patent/KR20120089696A/en not_active Application Discontinuation
- 2009-08-25 TW TW098128545A patent/TW201017739A/en unknown
-
2011
- 2011-08-01 US US13/195,583 patent/US20130093033A9/en not_active Abandoned
- 2011-08-01 US US13/195,605 patent/US20110287604A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5959957A (en) * | 1996-01-19 | 1999-09-28 | Canon Kabushiki Kaisha | Probe and a cantilever formed with same material |
US20060043512A1 (en) * | 2004-08-24 | 2006-03-02 | Oliver Steven D | Microelectronic imagers with optical devices having integral reference features and methods for manufacturing such microelectronic imagers |
US20090280595A1 (en) * | 2008-05-06 | 2009-11-12 | S.O.I. Tec Silicon On Insulator Technologies | Process for assembling wafers by means of molecular adhesion |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8932938B2 (en) | 2009-03-12 | 2015-01-13 | Soitec | Method of fabricating a multilayer structure with circuit layer transfer |
US8927320B2 (en) | 2009-06-26 | 2015-01-06 | Soitec | Method of bonding by molecular bonding |
WO2014001868A1 (en) * | 2012-06-28 | 2014-01-03 | Soitec | Method for producing composite structure with metal/metal bonding |
FR2992772A1 (en) * | 2012-06-28 | 2014-01-03 | Soitec Silicon On Insulator | METHOD FOR PRODUCING COMPOSITE STRUCTURE WITH METAL / METAL TYPE COLLAGE |
KR20150023507A (en) * | 2012-06-28 | 2015-03-05 | 소이텍 | Method for producing composite structure with metal/metal bonding |
US9905531B2 (en) | 2012-06-28 | 2018-02-27 | Soitec | Method for producing composite structure with metal/metal bonding |
KR102084541B1 (en) | 2012-06-28 | 2020-03-05 | 소이텍 | Method for producing composite structure with metal/metal bonding |
US20150044786A1 (en) * | 2013-08-09 | 2015-02-12 | Taiwan Semiconductor Manufacturing Company, Ltd. | Alignment Systems and Wafer Bonding Systems and Methods |
US9646860B2 (en) * | 2013-08-09 | 2017-05-09 | Taiwan Semiconductor Manufacturing Company, Ltd. | Alignment systems and wafer bonding systems and methods |
US10037968B2 (en) | 2013-08-09 | 2018-07-31 | Taiwan Semiconductor Manufacturing Company | Alignment systems and wafer bonding systems and methods |
Also Published As
Publication number | Publication date |
---|---|
FR2935537A1 (en) | 2010-03-05 |
US20130093033A9 (en) | 2013-04-18 |
US20110045611A1 (en) | 2011-02-24 |
JP2011524084A (en) | 2011-08-25 |
EP2319074A1 (en) | 2011-05-11 |
CN102017125A (en) | 2011-04-13 |
US20110278691A1 (en) | 2011-11-17 |
KR20100139023A (en) | 2010-12-31 |
WO2010023082A1 (en) | 2010-03-04 |
FR2935537B1 (en) | 2010-10-22 |
US8163570B2 (en) | 2012-04-24 |
KR20120089696A (en) | 2012-08-13 |
TW201017739A (en) | 2010-05-01 |
KR20120089695A (en) | 2012-08-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8163570B2 (en) | Method of initiating molecular bonding | |
US8927320B2 (en) | Method of bonding by molecular bonding | |
US9123631B2 (en) | Method for molecular adhesion bonding with compensation for radial misalignment | |
US8575002B2 (en) | Direct bonding method with reduction in overlay misalignment | |
JP5640272B2 (en) | Method for making multilayer structures by circuit layer transfer | |
US8232130B2 (en) | Process for assembling wafers by means of molecular adhesion | |
US8338266B2 (en) | Method for molecular adhesion bonding at low pressure | |
WO2012113799A1 (en) | Apparatus and method for direct wafer bonding | |
SG178659A1 (en) | Method for molecular adhesion bonding at low pressure |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |