EP3501042A1

EP3501042A1 - Method for connecting cross-components at optimised density

Info

Publication number: EP3501042A1
Application number: EP17764883.9A
Authority: EP
Inventors: François Marion; Lydie Mathieu; Frédéric Berger
Original assignee: Commissariat a lEnergie Atomique CEA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2016-08-18
Filing date: 2017-08-18
Publication date: 2019-06-26
Also published as: WO2018033689A1; FR3055166B1; US20210280628A1; CN109791920A; FR3055166A1

Abstract

The invention relates to a method for electrical connection by hybridisation of a first component (100) with a second component (200). The method comprises the following steps: forming pads of ductile material (111, 121) in contact respectively with connection zones (110, 120) of the first component (100); forming inserts (211, 221) of conductive material in contact with the connection zones (210, 220) of the second component (200); forming hybridisation barriers (212, 222) arranged between the inserts (211, 221) and electrically insulated from each other, said first and second hybridisation barriers (212, 222) serving as a barrier by containing the deformation of the pads of ductile material (111, 121) during the connection of the connection zones (210, 220) of the first component (100) with those of the second component (200). The invention also relates to an assembly (1) of two connected components (100, 200).

Description

INTERCOMPOSING CONNECTION METHOD WITH OPTIMIZED DENSITY

DESCRIPTION

TECHNICAL AREA

The invention relates to the field of microelectronics and optoelectronics and relates more particularly to the methods of connecting components of microelectronics and optoelectronics with each other and in particular the methods of vertical connection (also known by the names " hybridization "and" flipped chip ", and better known by their English name" flip-chip ").

The invention thus relates to a method of connecting two components together and an assembly comprising two components connected to each other.

STATE OF THE PRIOR ART

For some applications, such as optoelectronics, it may be necessary to connect components to each other. This is particularly the case for light detection applications in which the light capture component is generally integrated in a III-V semiconductor substrate, such as a gallium nitride GaN substrate, whereas the light capture component is generally integrated in a III-V semiconductor substrate, such as a gallium nitride GaN substrate. processing electronics for processing the signals obtained by the capture component is integrated in a silicon Si substrate.

To connect these components together, it is known to use the methods of vertical connection or hybridization. When implementing a method according to these methods and for connecting a first and a second component, the first and second components respectively comprise a first and a second connection face, the first connection face comprising at least a first and a second connection area to respectively connect to at least a third and a fourth corresponding area of the second connection face. The method comprises the following steps: forming a first and a second stud of ductile material, such as a first and second indium ball, in respective contact with the first and the second connection zone,

forming a third and a fourth pad of ductile material, such as a third and a fourth indium ball, in respective contact with the third and fourth connection zones,

connecting the first and second connection areas with respectively the third and fourth connection areas, the first and second connection areas being opposite the third and fourth connection areas and the connection being made by thermocompression.

In order to lower the temperature used during the connection step and to reduce the distance between the contact zones so as to increase the density of the connections, it is known from the documents WO2006 / 054005 and WO2009 / 115686 to provide in place of third and fourth pads of ductile material, a first and a second insert respectively in contact with the third and fourth connection zone.

In this way, during the step of connecting the first and second connection areas with the third and fourth connection areas, the first and the second insert will have a relatively small contact surface and adapted to fit into the plot of ductile material corresponding. This significantly reduces the temperature and pressure requirements for obtaining such an insertion. It is therefore possible to reduce the temperature and the pressure used during the thermocompression and therefore to better control the crushing of the stud of ductile material.

Nevertheless, even with such a control of the crushing of the stud of ductile material, the density of the connections that makes it possible to obtain such a connection method remains limited. Indeed, if we take a conventional dimensioning of ductile material pads of 3.5 μιη in diameter and inserts of the micro-tube type, as disclosed in document WO2009 / 115686, with a diameter of 2 μιη, it is necessary to have a step between the connection areas greater than 5 μιη to avoid any risk of short circuit between two adjacent connection areas. Such a constraint is related to the fact that during the connection, and therefore the insertion of the inserts in the studs of ductile material, the deformation of the studs of ductile material can be in the direction of adjacent zones and cause connections, that is, short circuits between adjacent studs of ductile material.

It is also known from US 2010/207266 to provide a hybridization barrier to avoid any risk of short circuit between two adjacent connection areas this even for significant connection densities.

Nevertheless, the manufacturing method taught by document US 2010/207266 is relatively complex since it requires a large number of deposition steps, especially to form the base, the inserts and the hybridization barriers, and thus requires costly steps of 'alignment.

STATEMENT OF THE INVENTION

The present invention aims to remedy this drawback and is therefore more precisely intended to provide a two-component connection method that does not present a risk of short-circuiting between two adjacent connection areas, this even for significant connection densities, said method being simpler than those of the prior art, such as that taught by US 2010/207266, which does not present a risk of short circuit between two connection areas.

The invention relates for this purpose to a method of electrical connection by hybridization of a first component to a second component, the first and second components respectively comprising a first and a second connection face, the first connection face comprising at least a first and a second connection area to respectively connect to at least a third and a fourth corresponding connection area of the second connection face,

the process comprising the following steps:

forming a first and a second stud of metal ductile material in respective contact with the first and the second connection zone, forming a first and a second insert made of conductive material in contact with the third and fourth connection areas respectively, the first and the second insert being intended to be inserted respectively into the first and second studs of ductile material; ,

the method further comprising the steps of:

forming on the second connecting face of at least a first and a second hybridization barrier arranged at least partly between the first and the second insert and electrically insulated from each other, said first and second barrier of hybridization being both positioned outside the orthogonally projected surfaces on the second connecting face of the first and second pads made of ductile material when the first and the second connection zone are placed opposite the third and fourth respectively connection zone, the first and the second hybridization wall being outside respectively the fourth and the third connection zone,

connecting the first and the second connection zone with respectively the third and the fourth insertion connection zone of the first and the second insert in respectively the first and the second stud of ductile material, the first and second connection zones being opposite the third and fourth connection zones and the first and second hybridization barriers serving as a barrier by containing the deformation of respectively the first and the second stud of ductile material towards the fourth and the fourth respectively. third connection area.

The first and the second insert are in a hollow form.

the method further comprising the following step:

connecting the first and second connection areas with respectively the third and fourth insertion connection regions of the first and second inserts in the first and second ductile material pads, respectively, the first and second connection areas being in contact with each other. with respect to the third and fourth connection areas and the first and second hybridization barrier barrier office by containing the deformation respectively of the first and the second stud of ductile material towards respectively the fourth and the third connection zone.

The step of forming the first and the second insert comprises the following sub-steps:

depositing a sacrificial layer on the second connection face, partial etching, of the sacrificial layer e in order to release a part of each of the connection zones corresponding to a portion of zone intended to be present between the insert and the barrier of corresponding hybridization,

depositing a layer of a metallic material for forming the first and the second insert and the first and second hybridization barrier,

polishing the second face so as to remove the portion of the layer of the metallic material which is in contact with the surface of the sacrificial layer which is opposite to the second connection face and retain the parts of the layer of the metal material 320 covering the previously released parts, said retained portions thus forming the conductive elements of the connection areas,

removing the sacrificial layer.

With such a connection method, there is no risk of short circuit between the third and the fourth zone regardless of the pitch between the third and the fourth connection zone. Indeed, the first and second hybridization barriers, by containing the deformation of the ductile material pads towards the other pad of ductile material, eliminate any risk of direct contact between the first and the second pad of ductile material. In addition, the first and second hybridization barrier being electrically insulated from each other, this insulation is used to electrically isolate the first and the second stud of ductile material electrically from one another.

With such hybridization barriers, it is therefore possible to have a high density of connections without risk of short circuit between two adjacent connection areas.

In addition, with such a method, the hybridization barriers are formed at the same time as the inserts. The result is a simplified process vis-à-vis those of the prior art for which the hybridization barriers are formed separately inserts.

During the formation step on the second connecting face of at least a first and a second hybridization barrier, the first and the second hybridization barrier can be formed respectively in contact with the third and the fourth zone of connection.

In this way, the first and second hybridization barriers being formed respectively in contact with the third and the fourth contact zone, the space between the third and fourth connection areas can be minimized since it is not occupied by hybridization barriers.

In forming the first and second hybridization barriers, the first and second hybridization barriers may be made of a conductive material.

Thus, the first and second hybridization barriers participate respectively in the electrical connection between the first ductile material pad and the third connection zone and between the second ductile material pad and the fourth connection pad.

The terms "conductor" and "insulator" when used above and in the rest of this document should be understood as "electrical conductor" and "electrical insulator".

The steps of forming the first and second insert and the first and second hybridization barrier can be carried out simultaneously, the first and the second insert and the first and second hybridization barrier being made of the same conductive material. .

Thus, the electrical connection between the first and the second component can be obtained with a reduced number of steps.

During the steps of forming the first and the second insert and the first and second hybridization barrier, the formation of the first insert and the first hybridization barrier consists in the formation of a first conductive element in contact with each other. the third connection zone, the formation of the second insert and the second hybridization barrier consists of forming a second conductive element in contact with the fourth connection zone.

During the steps of forming the first and second inserts and the first and second hybridization barriers, the first and second conductive elements may each be in the form of first and second cylindrical walls of revolution and concentric, each extending substantially perpendicular to the corresponding connection area surface, the first wall being surrounded by the second wall and forming the insert corresponding to said conductive element, the surface of the second wall facing the first wall forming the hybridization barrier corresponding to said conductive element.

In this way, the deformation of the first and second stud of ductile material takes place in all directions of the connection plane of the first and the second component. It is therefore possible to optimize the density of the connections between the first and second components in all directions of the connection plane.

The steps of forming the first and second insert and the first and second hybridization barrier may comprise the following substeps:

depositing a sacrificial layer on the second connection face,

partial etching of the sacrificial layer so as to release a part of each of the connection zones corresponding to the annular base of the conductive element to be formed

depositing a layer of a metallic material intended to form the conductive elements of the connection zones,

polishing the second face so as to remove the portion of the layer of the metallic material which is in contact with the surface of the sacrificial layer which is opposite to the second connection face and retain the parts of the layer of the metallic material covering the parts previously released, said conserved portions thereby forming the conductive elements of the connection areas,

removing the sacrificial layer. With such steps, it is possible to form the first and the second insert and the first and second hybridization barrier using microelectronic techniques, such as the damascene method.

During the step of forming the first and the second hybridization barrier, the first and second hybridization barrier may respectively surround the first and the second insert.

In this way, the deformation of the first and second stud of ductile material takes place in all directions of the connection plane of the first and second component. It is thus possible to optimize the density of the connections between the first and second components in all directions of the connection plane.

According to a possibility not within the scope of the invention, during the step of forming the first and the second insert, it can be formed a first and a second conductive element forming respectively the first and second in sert serves,

and during the step of forming the first and second hybridization barrier, at least a first non-conductive element at least partially positioned between the first and the second insert may be formed, the at least one first element insulator having a first surface facing the first insert forming the first hybridization barrier and a second surface facing the second insert forming the second hybridization barrier.

The use of such an insulating element makes it possible to obtain good electrical insulation between the third and the fourth connection zone. The risks of short circuit between the third and the fourth connection zone are thus particularly low.

The invention also relates to a set of two components connected to one another by hybridization,

wherein the first component has a first connection face comprising at least a first and a second connection area, each of the first and second connection areas, said first component further comprising contacting a first and a second pad of ductile material in contact respectively with the first and the second connection zone,

in which the second component comprises a second connection face comprising at least a third and a fourth connection zone vis-à-vis respectively the first and the second connection zone, the second component further comprising a first and a second insert in contact with respectively the third and fourth connection zone, the first and the second insert being respectively inserted in the first and second ductile material stud of the first and the second connection zone so as to ensure a connection between the first and the second connection zone and the third and the fourth connection zone respectively,

the second component further comprising on its second connecting face a first and second hybridization barrier arranged at least partly between the first and the second insert, the first and second hybridization wall being respectively outside the fourth and the third connection zone and acting as a barrier respectively to the first and the second stud of ductile material towards respectively the fourth and the third connection zone.

The first insert and the first barrier being connected by a first metal base formed solely between these two last, the second insert and the second barrier being connected by a second metal base formed solely between the latter two.

Such a set of components enjoys the advantages of the connection method according to the invention and thus unlikely to have short circuits this same with a density of connections between the first and the second optimized components.

The first and second hybridization barrier and the first and the second insert may be made of a conductive material.

The first insert and the first barrier may be provided by a first conductive element in contact with the first connection zone, the second insert and the second barrier being provided by a second conductive member in contact with the second connection zone.

In this way, the hybridization barriers can participate in the connections between the first and the third connection zone and between the second and the fourth connection zone.

According to a possibility not within the scope of the invention, the first and second hybridization barrier may be provided by at least one first insulating element, said at least one first insulating element having a first surface facing the first insert forming the first hybridization barrier and a second surface facing the second insert forming the second hybridization barrier.

Such an insulating element makes it possible to obtain good electrical insulation between the third and the fourth connection zone. The risks of short circuit between the third and the fourth connection zone are thus particularly low.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the description of exemplary embodiments, given purely by way of indication and in no way limiting, with reference to the appended drawings in which:

FIG. 1 is a schematic sectional view of a set of two components connected to each other by hybridization according to a first embodiment of the invention, the first component comprising two hybridization pads, the second component having two conductive elements forming inserts and hybridization barriers,

FIG. 2 is a schematic perspective view showing only the second component of the assembly illustrated in FIG. 1;

FIG. 3 is a close schematic sectional view on a connection zone of the first and second components of the assembly illustrated in FIG. 1 before the connection, FIG. 3 illustrating the design constraints of the hybridization barriers according to the invention. , FIGS. 4A to 4F illustrate the steps of forming conductive elements of the second component of the assembly illustrated in FIG. 1,

FIG. 5 illustrates a schematic view from above of a second component of an assembly according to this first embodiment of the invention for which twelve connections are provided,

FIG. 6 illustrates the main connection steps of the first component with the second component to form an assembly according to this first embodiment, such as that illustrated in FIG. 1,

FIGS. 7A to 7E illustrate schematic cross-sectional views of an assembly and a top view of the second component of the same assembly respectively according to the first to a sixth embodiment of the invention, FIG. 7A corresponding to the assembly according to the first embodiment, Figure 7B corresponding to an assembly according to a second embodiment not covered by the invention wherein the first and second hybridization barriers are formed by an insulating conductive element, Figure 7C corresponds to a set according to a fourth embodiment in which each of the inserts is a beveled insert, FIG 7D corresponding to an assembly according to a fifth embodiment not covered by the invention wherein each of the connection areas comprises a first and a second conductive element cylindrical ellipsoidal section each participating in the formation of the insert and the hybridization barrier, FIG. 7E corresponding to an assembly according to a sixth embodiment not covered by the invention wherein each of the connection areas comprises a conductive element forming the insert and a non-conducting element forming the hybridization barrier,

FIG. 8 illustrates four views from above of different shape configurations for the insert / hybridization barrier assembly compatible with the first embodiment, the view referenced a) corresponding to inserts and square section hybridization barriers, the view referenced b) corresponding to circular inserts and hybridization barriers of square section, the view referenced c) corresponding to circular inserts and hexagonal section hybridization barriers, the referenced view d) corresponds to solid circular inserts and hexagonal section hybridization barriers.

Identical, similar or equivalent parts of the different figures bear the same numerical references so as to facilitate the passage from one figure to another.

The different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

The different possibilities (variants and embodiments) must be understood as not being exclusive of each other and can be combined with one another.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

FIG. 1 represents an assembly 1 of two connected components 100, 200 whose connection has been obtained by means of a method according to a first embodiment of the invention. This first component 100 may thus be, for example, an optical sensor, such as a CCD or CMOS matrix, or an imager, such as an LCD matrix, to be connected to a second component, such as an optical sensor electronics. or imager. Thus, such a method is intended, as shown in FIG. 1, to connect semiconductor structures 102 of the first component 100 with semiconductor structures 202 of the second component.

The first component 100 may thus comprise a semiconductor support of a first type, such as a support in semiconductor material III-IV such as a support of the gallium nitride / corundum type, the second component comprising a semiconductor support of a second type, such as Si silicon support or Ge germanium.

To allow the connection of the first and second components

100, 200, such a set of two components 100, 200 comprises:

the first component 100 having a first connection face 101 comprising at least a first and a second connection zone 110, 120, said first component 100 further comprising a first and a second plot of ductile material 111, 121 in contact respectively with the first and the second connection zone 110, 120,

the second component 200 comprising a second connection face 201 comprising at least a third and a fourth connection zone 210, 220 vis-à-vis respectively the first and the second connection zone 110, 120, the second component 200 comprising in addition a first and a second insert 211, 221 in contact respectively with the third and the fourth connection zone 210, 220, the first and the second insert 211, 221 being respectively inserted into the first and second stud of ductile material 111, 121, the second component 200 further comprising on its second connection face a first and second hybridization barrier 212, 222 arranged at least partly between the first and the second insert 211, 221 and being electrically isolated from one another. on the other, the first and the second hybridization wall 212, 222 being outside respectively the fourth and the third connection zone 220, 210 and Barrier, respectively, to the first and second ductile material studs 111, 121 respectively to the fourth and third connection zones 210, 220.

The first component 100 has on the first connection face 101 the first and the second connection zone 110, 120. Each of the first and the second connection zone 110, 120 is formed by a metal layer acting as contact for the When a weld connection is sought, the metal layers forming the first and the second connection zone 110, 120 are made of a material that can be wetted by the material of the first and second pads made of ductile material 111, 121. such a characteristic is not necessary when a deformation connection is sought.

Each of the metal layers forming the first and the second connection zone 110, 120 may be made of a material selected from the group consisting of Au gold, Al aluminum, Ag silver, Ni nickel, Pt platinum, palladium Pd and their alloys.

According to a possibility of the invention not illustrated in which a connection by welding is sought, these same metal layers forming the first and second connection areas 110, 120 may be formed of a first metal sub-layer to contact one of the areas of the first structure 102 and a second metal sub-layer covering the first metal layer and being realized in a wettable material to the material of which are formed the pads of ductile material 111, 121.

By material wettable by the material in which are made the first and second pads of ductile material 111, 121, it should be understood here and in the remainder of this document that the wettable material has a total wettability vis-à-vis the material of studs of ductile material. In other words, the spreading coefficient S of the material of the pads of ductile material, when in the liquid state, is strictly positive.

The first and second connection zones 110, 120 are respectively provided with the first and second studs made of ductile material 111, 121. Each of the first and second studs made of ductile material 111, 121 is made of a ductile metallic material such as aluminum. 'indium. Thus, the material of the first and second stud of ductile material 111, 121 may be selected from the group comprising indium in, tin Sn, aluminum Al, copper Cu, zinc Zn and their alloys, such as the tin alloys SnPb lead-tin alloys and SnAgCu copper-silver-tin alloys.

Thus, if we take the example of a solder connection, the first and the second stud of ductile material can be made of indium In, Sn tin or one of its alloys such as lead-tin alloys SnPb and copper-silver-tin alloys SnAgCu, the first and second connection zones that can be made in Au gold.

On the other hand, if one takes the example of a connection obtained by deformation, the first and the second stud made of ductile material may be made of aluminum Al, copper Cu or zinc Zn, the first and the second connection zones being be made of Al aluminum, Cu copper or Zn zinc.

It can be seen in FIG. 2 that the second component 200 has on the second connection face 201 the third and the fourth connection zone 210, 220,. Each of these third and fourth connection areas 210, 220 is formed by a metal layer acting as contact for the structure 201. When a solder connection is desired, the metal layers forming the third and fourth connection areas 210, 220 are made of a material wettable by the material of the first and second pads ductilelll material, 121. Each of the metal layers forming the third and fourth connection zone 210, 220 may be made of a material selected from the group consisting of Au gold, Al aluminum, Ag silver, Ni nickel, Pt platinum, Pd palladium and their alloys. .

Of course, according to a possibility of the invention not illustrated in which a connection by welding is sought, and similarly to the first and second connection areas 110, 120, the metal layers forming the third and fourth connection areas 210, 220 may also be formed of a first metal sub-layer for contacting one of the zones of the second structure 202 and a second metal sub-layer covering the first metal layer and being made of a wettable material whose material is made the pads of ductile material 111, 121.

The third and the fourth connection zone 210, 220 are respectively provided with a first and a second conductive element 215, 225. The first element 215 comprises both the first insert 211 and the first hybridization barrier 212, while the second element 225 includes both the second insert 221 and the second hybridization barrier 222. The first and the second conductive element 215, 225, as shown in FIG. 2, are each in the form of a first and second cylindrical walls of revolution and concentric and which extend perpendicular to the surface of the corresponding connection area 210, 220. Thus the first and the second cylindrical wall of each of the first and second conductive elements 215, 225 have their axis of revolution perpendicular to the same surface of the corresponding connection area 210, 220. For each of the first and second conductive elements 215, 225, the first wall is internal to the second wall, that is to say, it is surrounded by the second wall. Each of the first and second conductive elements 215, 225 also comprises an annular base in contact with the corresponding connection zone 210, 220 and connecting the first and the second wall of said conductive element 215, 225 to each other. The first and second conductive elements 215, 225 are made of a metallic material selected from the group comprising copper Cu, titanium Ti, tungsten W, chromium Cr, nickel Ni, platinum Pt, palladium and their alloys, such as tungsten silicide WSi, tungsten nitride WN and titanium nitride TiN. According to an advantageous possibility of the invention, the metallic material of the first and second conductive element 215, 225 is Cu copper.

According to a possibility of the invention, each of the conductive elements 215, 225 may further comprise a metal coating, such as a gold layer, in order to protect the metal material of which it is made from oxidation.

The first and second conductive elements 215, 225 are dimensioned such that:

the first wall of the first and second conductive elements 215, 225 are disposed within a surface respectively corresponding to the orthogonally projected surface of the first and second ductile material studs 111, 121 when the first and second connection 110, 120 are placed opposite the third and the fourth connection zone 210, 220 respectively,

the second wall of the first and second conductive elements are arranged outside a surface respectively corresponding to the orthogonally projected surface of the first and second ductile material studs 111, 121 when the first and the second connection zone 110, 120 are connected to the third and fourth connection areas 210, 220, respectively.

It will further be noted that the first and the second conductive elements 215, 225 being formed in contact with respectively the third and the fourth connection zone 210, 220, the second wall of the first and second conductive elements 215, 225, by a such dimensioning, is outside respectively the fourth and third connection zone 220, 210. In the same way, the first and second conductive elements 215, 225 are at a distance from each other, this without it there is any electrical connection between them. The first and second conductive elements are electrically isolated from each other. So the first and second Hybridization barriers 212, 222 formed respectively by the second wall of the first and second conductive elements 215, 225, are also electrically insulated from each other.

Thus, with such a dimensioning and as illustrated in FIG. 1, the first wall of the first and second conductive elements 215, 225 respectively form the first and the second inserts 211, 221, and the internal surface of the second wall of the first and second the second conductive element 215, 225 form respectively the first and the second hybridization barrier 212, 222.

It should be noted that from a practical point of view and as illustrated in FIG. 3, such sizing conditions can generally be obtained by following the following conditions:

(1) d10 <d20 <d25

(2) hl0 ~ h20,

d10 and d25, being respectively the outer diameter of the first wall and the inside diameter of the second wall of said conductive element 215, 225 among the first and the second conductive element 215, 225, h10 the height of said first and second walls, d20 , h20 the maximum lateral dimension and the maximum height of the pad of ductile material 111, 121 corresponding to said conductive element 215, 225.

Of course, these dimensions as regards the studs of ductile material 111, 121, correspond to the dimensions of the latter before connection of the first component 100 with the second component 200, the stud of ductile material 111, 121 being subject to deformation during the connection. In the same way, such a dimensioning is valid for a configuration in which during the assembly of the first and the second component 100, 200, the stud made of ductile material 111, 121 is placed opposite the corresponding conducting element. The outer diameter d 10 of the first wall and the inner diameter d 25 of the second wall of the first and second conductive elements 215, 225 can of course be chosen to compensate for any misalignment between the conductive element 215, 225 and the stud made of ductile material. 111, 121 corresponding, this by undersizing the outer diameter of the first wall and over-dimensioning the inner diameter of the second wall vis-à-vis the dimensions of the stud of ductile material 111, 121.

FIGS. 4A to 4E illustrate a process for forming conductive elements 235, 245, 255, 265, on the connection zones 230, 240, 250, 260 of a second component 200 according to this first embodiment, said component which comprises two second structures 202a, 202b, each connected by means of two respective connection zones 230, 240, 250, 260. Such a formation method comprises the following steps:

supplying, as illustrated in FIG. 4A of the second component 200, each of the connection zones 230, 240, 250, 260 formed by a respective metal layer,

deposition, as illustrated in FIG. 4B, of a sacrificial layer 310 intended to form a hard mask, said sacrificial layer having a thickness greater than the desired height h10 for the first and second conductive elements 215, 225 to be formed,

partial etching, as illustrated in FIG. 4C, of the sacrificial layer 310 so as to release the part 311, 312 of each of the connection zones 320 corresponding to the annular base of the conductive element to be formed,

deposition, as illustrated in FIG. 4D, of a layer of the metallic material 320 intended to form the conductive elements 235, 245, 255, 265 of the connection zones 230, 240, 250, 260,

polishing, as illustrated in FIG. 4E, of the layer of the metallic material 320 and of a portion of the sacrificial layer 310 so as to remove the part of the layer of the metallic material 320 covering the sacrificial layer 310 and to retain the parts of the layer of the metallic material covering the previously released portions 311, said parts of the layer of the metallic material 320 conserved thus forming the conducting elements 235, 245, 255, 265 of the connection zones 230, 240, 250, 260,

removing the sacrificial layer 310, as shown in Figure 4F. It should be noted that such a method, especially when the materials of the sacrificial layer 310 and of the layer of the metallic material 320 are silicon dioxide Si0 ₂ and copper Cu respectively, has the advantage of using a technique classic and perfectly mastered of the microelectronics industry that is the damascene etching technique. It is thus possible to produce, with such a method, second components comprising a large number of connection zones 230, 240, 250, 260, 270, 280 organized, for example and as illustrated in FIG. 5, in the form of a matrix with optimized connection density. The dimensioning and positioning of these connection areas are then controlled at the scale of one hundred nanometers and it is possible to consider steps between areas less than 5 μιη.

Indeed, we can take the concrete example for such a step of 5 μιη, a screen WUXGA format, that is to say having a resolution of 1920x1080 and requiring more than 2 million connections, realized in a gallium nitride GaN as the first component 100 to connect to a second component 200 which is a control circuit in CMOS technology on silicon. To allow the connection of this screen as the first component 100, each of the connection areas 111 of the first component 100 may be equipped, with reference to FIG. 3, with a respective ductile material stud 111 having a diameter d20 of 3 μιη and a height h20 of 2.5 μιη. The control circuit may comprise on each of these connection zones 210 a conductive element 215 with a height of 2.5 μιη and whose outside diameters of the insert and inside of the hybridization barrier d25, d10 are respectively equal to 1.5 μιη and 3.5 μιη.

In this way, equations (1) and (2) being respected, the more than 2 million connections between the screen and the control circuit can be done with a step of 5 μιη without risk of short circuit between two zones. adjacent connection, this thanks to the hybridization barriers which will allow to contain the deformation of the pads of ductile material 211, 221. The first and second components 100, 200 according to this first embodiment can be connected to one another according to a connection method. Such a connection method comprises the following steps:

forming the first and second studs made of ductile material 111, 121 in respective contact with the first and the second connection zone 110, 120,

forming the first and second conductive elements in contact with respectively the third and the fourth connection zone 210, 220 so as to thus form the first and second inserts 211, 221 made of conductive material, and the first and the second barrier of hybridization 212, 222 arranged at least partly between the first and the second insert and electrically insulated from each other,

connecting the first and the second connection zone 110, 120 with respectively the third and the fourth connection zone 210, 220 by insertion of the first and second inserts 211, 221 in respectively the first and the second stud of ductile material 111 , 121, the first and second connection areas 110, 120 facing the third and fourth connection areas 210, 220 and the first and second hybridization barriers 212, 222 acting as a barrier containing the deformation respectively the first and the second stud of ductile material 111, 121 towards respectively the fourth and the third connection zone 220, 210.

The step of providing the first and second conductive element 215, 225 may be a step of implementing the method of manufacturing the second component 200 already described.

The connection step is ideally a connection step comprising two substeps of compression, such as those described in WO2009 / 115686. Such sub-steps are, with reference to FIG. 6:

aligning the first and second components 100, 200 so as to bring the first and the second connection area 110, 120 with the third and the fourth connection area 210, 220, respectively, as illustrated in a) on Figure 6 partially inserting the first and second inserts 211, 221 in respectively the first and the second ductile material 111, 121, as illustrated in b) in FIG. 6,

final insertion of the first and second inserts 211, 221, in respectively the first and the second stud of ductile material 111, 121, as illustrated in c) in Figure 6.

It may be noted that in order to reduce the thermal impact and to avoid air entrapment between each of the ductile material pads 111, 121 and the corresponding insert 211, 212, the two insertion sub-steps can be realized. at room temperature and the final insertion step can be carried out in a low pressure environment such as primary vacuum (that is to say a pressure between 1000 and 1.10 ^" ³ mbar).

It will be noted that the alignment being obtained before the partial insertion and being perpetuated by the partial insertion, the final insertion step can be performed by means of a press without alignment system.

FIGS. 7A to 7E illustrate different embodiments of the invention which differ mainly in the shape of the first and second hybridization barriers 212, 222 and the first and second inserts 211, 221, some of these embodiments 'being not covered by the invention.

Thus FIG 7A illustrates an assembly 1 according to the first embodiment with above a schematic sectional view of the assembly 1 and above a top view of the second component 200. This figure being similar to Figures 1 to 3, we refer the reader to the description that has already been made.

FIG. 7B illustrates an assembly 1 according to a second embodiment not covered by the invention in which the first and second hybridization barriers 212, 222 are provided by means of a non-conductive element 216, the inserts 211, 221 being provided by conductive elements 215, 225 according to the principle described in document WO2009 / 115686. Such an assembly 1 according to this second embodiment differs from an assembly 1 according to the first embodiment by the shape of each of the conductive elements 215, 225 providing the inserts 211, 221 and the presence of a non-conductive element 216 providing the first and the second hybridization barrier 212, 222.

In this second embodiment not covered by the invention, the non-conductive element 216 is a wall made of an electrically insulating material, such as for example that forming the sacrificial layer 310 during the formation of the conductive elements 215, 225, disposed between the third and the fourth connection zone 210, 220. The surface of the non-conductive element 216 facing the third connection zone 210 thus forms the first hybridization barrier 212 while the other surface, which makes therefore facing the fourth connection zone 220, forms the second connection barrier 222.

Since the non-conductive element 216 is made of an electrically insulating material, the first and second hybridization barriers are electrically isolated from one another. There is therefore no risk of a short circuit between the first and the second pad of ductile material 111, 121 when these first and second hybridization barriers 212, 222 contain the deformation of the pads made of ductile material 111, 121.

The first and second conductive elements 215, 225 being of the same type as the inserts described in the document WO2009 / 115686, the first and second conductive elements 215, 225 are disposed on a surface respectively corresponding to the projected surface orthogonally of the first and second plot of ductile material 111, 121 when the first and the second connection area 110, 120 are placed opposite the third and fourth connection areas 210, 220, respectively.

The non-conductive element 216, being disposed outside the third and fourth connection zones 210, 220, is outside the orthogonally projected surface of the first and second ductile material studs 111, 121 when the first and second connection zone 110, 120 are placed opposite the third and fourth connection zones 210, 220, respectively.

The method of forming the conductive elements 215, 225 and the non-conductive element 226 of a second component 200 according to this second embodiment of embodiment not covered by the invention differs from the method of forming the conductive elements 215, 225 according to the first embodiment in that during the step of removing the sacrificial layer 310, the deletion is only partial, a part of the sacrificial layer 310 being retained to form the non-conductive element 216.

FIG. 7C illustrates an assembly 1 according to a third embodiment in which each of the first and second conductive elements 215, 225 has its bevelled internal portion so as to favor the insertion of each of the first and second inserts 211, 221 in the stud. of ductile material 111, 112 corresponding. An assembly according to this fourth embodiment differs from an assembly according to the first embodiment of the beveled shape of the inner portion of each of the first and second conductive elements 215, 225.

Thus, each of the first and second conductive members 215, 225 has the beveled inner cylinder portion. The corresponding insert 211, 221 is thus also beveled according to a principle similar to that described in WO2009 / 115686 and the force required for the connection of the first and second components 100, 200 is lowered.

FIG. 7D illustrates an assembly 1 according to a fourth embodiment of the invention not covered by the invention in which each of the third and fourth connection zones 210, 210 is provided with two conductive elements 215a, 215b, 225a, 225b. An assembly 1 according to this fourth embodiment differs from an assembly 1 according to the first embodiment in that there is provided a first and a second conductive element 215a, 215b in contact with the first connection zone 210 and a third and fourth conductive elements 225a, 225b in contact with the second connection zone 220, and in that the first, second, third and fourth conductive elements 215a, 215b, 225a, 225b have a cylindrical shape of elliptical section.

The first, second, third and fourth conductive elements 215a, 215b, 225a, 225b are each in the form of an envelope cylindrical elliptical section, the axis of the foci being substantially perpendicular to a line passing through the third and fourth connection area 210, 220.

The first and the second conductive elements 215a, 215b are arranged in central symmetry with respect to the center of the first connection zone 210. In this way, the wall of each of the first and second conductive elements proximal to the center of the first connection zone 210 forms the first insert 211, while the wall of each of the first and second conductive elements 215a, 215b distal from the center of the first connection zone 210 forms the first hybridization barrier 212.

Similarly, the third and fourth conductive elements 225a, 225b are arranged in a central symmetry with respect to the center of the second connection zone 220. The wall of each of the third and fourth conductive elements 225a, 225b, proximal from the center of the first connection zone 210, forms the second insert 221, while the wall of each of the third and fourth conductive elements, distal from the center of the second connection zone 220, forms the second hybridization barrier 222.

The sizing of the first to fourth conductive elements 215a, 215b, 225a, 225b is adapted so that:

the proximal wall portions of the first, second, third and fourth conductive members 215a, 215b, 225a, 225b are disposed within a corresponding surface for the first and second conductive members 215a, 215b at the orthogonally projected surface of the first ductile material stud 111, and for the third and fourth conductive elements 225a, 225b to the orthogonally projected surface of the second ductile material stud 121, when the first and the second connection areas 110, 120 are exposed. with respect to the third and the fourth connection zone 210, 220 respectively,

the distal wall portions of the first, second, third and fourth conductive elements 215a, 215b, 225a, 225b are arranged outside a corresponding surface, for the first and second conductive elements 215a, 215b to the orthogonally projected surface of the first stud of ductile material 111, and for the third and fourth conductive elements 215a, 225b to the orthogonally projected surface of the second stud 121, this when the first and the second connection zone 110, 120 are placed opposite the third and the fourth zone respectively. connection 210, 220.

The method of forming connection elements 215a, 215b,

225a, 225b according to this fourth embodiment not covered by the invention may be a method of the same type as that described in WO 2011/115686, the shape and positioning of the inserts formed during the process document WO2011 / 115686 having just to be adapted to match those of the connecting members 215a, 215b, 225a, 225b according to this fourth embodiment.

FIG. 7E illustrates an assembly 1 according to a fifth embodiment not covered by the invention in which the first and the second connection zone 110, 120 are respectively surrounded by a first and a second non-conductive element 216, 226 and are in contact with a first and a second conductive element 215, 225 respectively. An assembly according to this fifth embodiment differs from an assembly according to the first embodiment in that it comprises a first and a second non-conducting element. 216, 226 forming respectively the first and the second hybridization barrier 212, 222, the first and the second conductive element 215, 225 forming the first and the second insert 211, 221.

In this fifth embodiment not covered by the invention, the first and the second connection zone 210, 220 are respectively surrounded by the first and the second non-conductive element 216, 226. Each of the first and second non-conductive elements 216, 226 is formed by a wall of non-conductive material. According to an advantageous possibility of this embodiment, and when the material of the sacrificial layer 310 is insulating, each of the first and the second insulating element 216, 226 is made of the same material as that of the sacrificial layer.

Similarly to the second embodiment not covered by the invention, the first and the second conductive element 215, 225 are of the same type. than those of the second embodiment. Thus, the first and second elements are arranged on a surface respectively corresponding to the orthogonally projected surface of the first and second ductile material studs 111, 121 when the first and second connection areas 110, 120 are facing each other. screw respectively the third and fourth connection area 210, 220.

The non-conductive elements 216, 226 being disposed outside the first and second connection zone 210, 220 are also outside the orthogonally projected surface of the first and second ductile material studs 111, 121 when the first and second second connection zone 110, 120 are placed opposite the third and the fourth connection zone 210, 220, respectively.

The method of forming conductive elements 215, 225 and non-conductive elements 216, 226 of a second component 200 according to this fifth embodiment not covered by the invention is similar to the forming method according to the second embodiment. Thus, the method for forming conductive elements 215, 225 and non-conductive elements 216, 226 differs from a method for forming conductive elements 215, 225 according to the second embodiment in that during the suppression step of the sacrificial layer 310, the suppression is only partial, parts of the sacrificial layer 310 being retained to form the first and the second non-conductive element 216, 226.

If in the various embodiments described above the conductive and insulating elements are cylindrical in shape of revolution or elliptical section, the invention is not limited to these types of shape. Thus, the invention covers any type of shape as long as each of the connection zones of the second component comprises:

an insert 211, 221 is inserted into a stud made of ductile material

111, 121 corresponding to the first component 100,

at least one hybridization barrier 212, 222 positioned outside the orthogonally projected surfaces on the second connecting face of the corresponding ductile material stud 111, 121 when the connection zone 210, 220 is placed opposite the corresponding connection area 110, 120 of the first component 100 the first and second barriers 212, 222, 232, 242, 252, 262 respectively surrounding the first and second inserts 211, 221, 231, 241, 251, 261, the first insert and the first barrier being connected by a first base metal formed solely between these two last, the second insert and the second barrier being connected by a second metal base formed solely between the latter two.

Thus, FIG. 8 illustrates four examples of form inserts 211, 221 and hybridization barriers 212, 222 compatible with the invention. In a) of FIG. 8, the insert 211, 221 and the hybridization barrier 212, 222 are provided by a conductive element 215, 225 in the form of a cylindrical double wall envelope of cubic section.

In b) of Figure 8, the insert 211, 221 is provided by a cylindrical envelope of circular section while the hybridization barrier 212, 222is provided by a cylindrical envelope of square section, each of these envelopes being provided for a connection zone 210, 220, by a single conductive element 215.

In c) of Figure 8, the insert 211, 221 is provided by a cylindrical envelope of circular section while the hybridization barrier 212, 222 is provided by a cylindrical envelope of hexagonal section, each of these envelopes being provided, for a connection zone 210, 220, by a single conductive element 215.

In d) of FIG. 8, the insert 211, 221 is provided by a solid cylinder of circular section while the hybridization barrier 212, 222 is provided by a cylindrical envelope of hexagonal section, each of this cylinder and this envelope being provided, for a given connection area 210, 220, by a single conductive element 215.

Claims

1. A method of electrical connection by hybridization of a first component (100) to a second component (200), the first and second components (100, 200) respectively comprising a first and a second connection face (101, 201), the first connection face (101) having at least a first and a second connection area (110, 120) to be connected respectively to at least a third and a fourth connection area (210, 220, 230, 240, 250, 260 ) corresponding to the second connection face (201),

the process comprising the following steps:

- forming a first and a second pad of ductile material (111, 121) metal in respective contact with the first and the second connection area (110, 120),

forming a first and a second insert (211, 221, 231, 241, 251, 261) made of conductive material in contact with the third and the fourth connection zone (210, 220, 230, 240, 250 respectively); , 260), the first and second inserts (211, 221, 231, 241, 251, 261) being intended to be inserted in respectively the first and the second stud of ductile material (111, 121), the first and the second second insert in a hollow form,

the electrical connection method being characterized in that

during the step of forming the first and second insert is also formed on the second connecting face (201) at least a first and a second hybridization barrier (212, 222, 232, 242, 252, 262) disposed at least partly between the first and second inserts (211, 221, 231, 241, 251, 261) and electrically isolated from each other, said first and second hybridization barriers (212, 222, 232, 242, 252, 262) are both positioned outside the orthogonally projected surfaces on the second connection face (201) of the first and second ductile material pads (111, 121) when the first and the second connection area (110, 120) are placed opposite the third and the fourth connection zone (210, 220, 230, 240, 250, 260), the first and the second wall respectively. the second and fourth connection regions (220, 210, 230, 240, 250, 260), the first and the second barrier ( 212, 222, 232, 242, 252, 262) respectively surrounding the first and the second insert (211, 221, 231, 241, 251, 261),

the method further comprising the following step:

- connection of the first and second connection area (110,

120) with the third and fourth connection regions (210, 220, 230, 240, 250, 260) respectively by inserting the first and second inserts (211, 221, 231, 241, 251, 261) respectively in the first and the second stud of ductile material (111, 121), the first and second connection regions (110, 120) facing the third and fourth connection regions (210, 220, 230, 240, 250, 260) and the first and second hybridization barriers (212, 222, 232, 242, 252, 262) acting as a barrier containing the deformation of respectively the first and the second pad of ductile material (111,

121) towards respectively the fourth and the third connection zone (210, 220, 230, 240, 250, 260),

and wherein the step of forming the first and second inserts comprises the following substeps:

depositing a sacrificial layer (310) on the second connection face,

partial etching, of the sacrificial layer (310) so as to release a portion (311) of each of the connection zones (320) corresponding to a portion of zone intended to be present between the insert and the corresponding hybridization barrier; ,

depositing a layer of a metallic material (320) for forming the first and the second insert and the first and second hybridization barrier,

polishing the second face so as to remove the portion of the layer of the metallic material (320) which is in contact with the surface of the sacrificial layer (310) which is opposite to the second connection face and retain the parts of the layer metal material (320) covering the parts (311) previously released, said retained portions thus forming the conductive elements (235, 245, 255, 265) of the connection areas (230, 240, 250, 260),

removing the sacrificial layer (310).

2. An electrical connection method according to claim 1 wherein in the forming step on the second connection face (201) of at least a first and a second hybridization barrier (212, 222, 232, 242, 252, 262), the first and second hybridization barriers (212, 222, 232, 242, 252, 262) are respectively formed in contact with the third and fourth connection regions (210, 220, 230, 240, 250, 260).

3. An electrical connection method according to claim 2 wherein during the formation of the first and second hybridization barrier (212, 222, 232, 242, 252, 262), the first and second hybridization barriers ( 212, 222, 232, 242, 252, 262) are made of a conductive material.

4. An electrical connection method according to claim 3, wherein the first and the second insert (211, 221, 231, 241, 251, 261) and the first and the second hybridization barrier (212, 222, 232, 242 , 252, 262) are made of the same conductive material.

5. An electrical connection method according to claim 4 wherein during the steps of forming the first and second insert (211, 221, 231, 241, 251, 261) and the first and second hybridization barrier (212). , 222, 232, 242, 252, 262), forming the first insert (211) and the first hybridization barrier (212) consists of forming a first conductive element (215) in contact with the third zone connection (210), forming the second insert (221) and the second hybridization barrier (222) comprises forming a second conductive member (225) in contact with the fourth connection area (220).

6. An electrical connection method according to claim 5 wherein during the steps of forming the first and second insert (211, 221) and the first and the second hybridization barrier (212, 222), the first and second conductive elements (215, 225) are each in the form of first and second cylindrical walls of revolution and concentric, each extending substantially perpendicular to the corresponding connection area surface (210, 220), the first wall being surrounded by the second wall and forming the insert (211, 221) corresponding to said conductive member (215, 225), the surface of the second wall facing the first wall forming the hybridization barrier (212, 222) corresponding to said conductive element (215, 225).

7. Set (1) of two components (100, 200) connected to one another by hybridization,

wherein the first component (100) has a first connection face (101) comprising at least a first and a second connection area (110, 120), each of the first and second connection area (110, 120), said first component (100) further comprising in contact a first and a second pad of ductile material (111, 121) in contact respectively with the first and second connection regions (110, 120),

wherein the second component (200) has a second connection face (201) comprising at least a third and a fourth connection area (210, 220) facing the first and second connection areas ( 110, 120), the second component (200) further comprising a first and a second insert (211, 221) in contact with the third and fourth connection regions (210, 220), the first and the second insert respectively. (211, 221) being respectively inserted into the first and second ductile material pads (111, 121) of the first and second connection areas (110, 120) so as to provide an electrical connection between the first and the second second connection zone (110, 120) and respectively the third and fourth connection zone (210, 220), the first and the second insert being in a hollow form,

said assembly (1) being characterized in that the second component (200) further comprises on its second connection face (201) a first and second hybridization barriers (212, 222) arranged at least partly between the first and the second insert (211, 221), the first and the second hybridization wall (212, 222) being respectively outside the fourth and the third connection zone (220, 210) and acting as a barrier respectively to the first and the second stud of ductile material (111, 121) in the direction of respectively the fourth and the third connection zone (210, 220) the first and second barriers (212, 222, 232, 242, 252, 2620) respectively surrounding the first and second inserts (211, 221, 231, 241, 251, 261), the first insert and the first barrier being connected by a first metal base formed solely between these two last, the second insert and the second barrier being connected by a second metal base formed solely between the latter two.

8. Assembly (1) according to claim 7, wherein the first and second hybridization barrier (212, 222) and the first and the second insert (211, 221) are made of a conductive material.

The assembly (1) according to claim 8, wherein the first insert (211) and the first barrier (221) are provided by a first conductive member (215) in contact with the first connection area (210), the second insert (221) and the second barrier (222) being provided by a second conductive member (225) in contact with the second connection area (220).