Method for manufacturing a substrate comprising a plurality of tiles

Abstract

The invention relates to a method for manufacturing a substrate (100), referred to as a donor pseudo-substrate, comprising a plurality of tiles (1) arranged at a distance from one another on a support substrate (3), comprising the steps of: - arranging, on the support substrate (3), said tiles (1) and an intermediate substrate (2) comprising a plurality of through-openings (20), such that each tile (1) extends into a respective through-opening (20) of the intermediate substrate, and - performing chemical-mechanical polishing of the tiles (1) arranged in the openings of the intermediate substrate.

Description

[0001] METHOD FOR MANUFACTURING A SUBSTRATE COMPRISING A PLURALITY OF PAVING PANELS

[0002] TECHNICAL FIELD

[0003] The invention relates to a method for manufacturing a substrate, called a pseudo-donor substrate, comprising a plurality of tiles, as well as a method for transferring chips from said tiles onto a receiving substrate.

[0004] STATE OF THE ART

[0005] In the field of microelectronics, optics or optoelectronics, the design of multilayer structures sometimes requires transferring tiles in the form of portions of a layer from a donor substrate to a support substrate or receiving substrate.

[0006] This type of process is generally referred to as a paving process, and involves a partial transfer of a layer taken from the donor substrate to form one or more paving stones arranged in a predetermined pattern or location on the supporting substrate.

[0007] Such tiling may be made necessary by a size difference between the donor substrate and the support substrate. Indeed, due to this size difference, it is not possible to transfer a layer of the donor substrate covering the entire surface of the support substrate.

[0008] A well-known layer transfer method is the Smart Cut™ method, in which an embrittlement zone is formed by implantation of atomic species into the donor substrate, delimiting the layer to be transferred, the donor substrate is bonded to the support substrate, and the donor substrate is detached along the embrittlement zone to transfer the layer from the donor substrate to the support substrate. However, this method assumes that the donor substrate and the support substrate are of identical size.

[0009] However, while silicon substrates are available with a relatively large size, typically a diameter of 300 mm, other materials of interest currently only exist in the form of bulk substrates of smaller size, for example 10 or 15 cm in diameter. Furthermore, these materials of interest are sometimes particularly expensive, so it is desirable to minimize any waste formed during transfer.This is particularly the case for III-V semiconductor materials, including nitrides (e.g., for binary compounds, indium nitride (InN), gallium nitride (GaN) and aluminum nitride (AIN)), arsenides (e.g., for binary compounds, indium arsenide (InAs), gallium arsenide (GaAs) and aluminum arsenide (AlAs)), and phosphides (e.g., for binary compounds, indium phosphide (InP), gallium phosphide (GaP) and aluminum phosphide (AlP)).

[0010] Instead of transferring an entire layer of the donor substrate, a solution based on the Smart Cut™ process consists of removing one or more blocks from at least one donor substrate and transferring said blocks onto an intermediate support, to form a substrate called a pseudo-donor substrate, forming by implantation of atomic species a weakening zone in each block, bonding the pseudo-donor substrate to a receiving substrate via the blocks, and detaching each block along the weakening zone so as to transfer a portion of each block onto the receiving substrate.

[0011] To allow the bonding of the donor pseudo-substrate to the receiving substrate, the free surface of all the paving stones must extend in the same plane. To this end, before bonding, chemical mechanical polishing (CMP) could be carried out, preferably preceded by mechanical abrasion (called "grinding" in English) of the donor pseudo-substrate. Chemical mechanical polishing combines the mechanical action of a polishing pad and the chemical action of a polishing solution to planarize the surface of all the paving stones.

[0012] However, if the distance between the tiles is large, typically greater than or equal to 250 pm, the polishing pad, which has a certain flexibility, partially inserts itself into the gap between the tiles and thus erodes the edges of the tiles. This rounding of the edges, which is called "edge rounding" in English, reduces the useful surface area of ​​the chips transferred to the receiving substrate. Conversely, the edges of the tiles very quickly degrade the polishing pad, which must therefore be renewed frequently.

[0013] SUMMARY OF THE INVENTION

[0014] An aim of the invention is therefore to design a method for manufacturing a pseudo-donor substrate without rounding the edges of the paving stones, even when the paving stones are far from each other.

[0015] To this end, the invention proposes a method for manufacturing a substrate, called a donor pseudosubstrate, comprising a plurality of blocks arranged at a distance from each other on a support substrate, comprising:

[0016] - arranging, on the support substrate, said paving stones and an intermediate substrate comprising a plurality of through openings, such that each paving stone extends into a respective through opening of the intermediate substrate, and

[0017] - chemical-mechanical polishing of the paving stones arranged in the openings of the interlayer substrate. The interlayer substrate is made of a different material from that of the paving stones or of a material with a composition similar to that of the paving stones but of lower quality.

[0018] The use of the interlayer substrate helps protect the edges of the paving stones during chemical-mechanical polishing. It therefore helps prevent the edges of the paving stones from rounding.

[0019] According to other advantageous but optional characteristics, possibly combined when technically possible:

[0020] - a distance between two adjacent blocks is greater than or equal to 1 mm, preferably greater than or equal to 2 mm;

[0021] - a distance between each block and an edge of the respective through opening is less than or equal to 250 pm, preferably less than or equal to 100 pm;

[0022] - the blocks comprise a semiconductor material, such as a III-V material;

[0023] - the interlayer substrate is formed by cutting openings through a silicon or silicon oxide substrate, in particular by means of a laser or a water jet;

[0024] - the interlayer substrate is formed by an additive manufacturing process;

[0025] - the intercalary substrate is formed from a semiconductor substrate bonded to a handling substrate via a dielectric layer, the openings being formed by selective etching of the semiconductor material down to the dielectric layer;

[0026] - the interlayer substrate has a thickness less than or equal to the thickness of the paving stones;

[0027] - the method comprises, after the implementation of the chemical-mechanical polishing, a removal of the interlayer substrate;

[0028] - the method comprises forming a weakening zone in the blocks, so as to delimit a respective chip in each block;

[0029] - the paving stones are placed on the support substrate before the intermediate substrate;

[0030] - the interlayer substrate is placed on the support substrate before the paving stones.

[0031] A pseudo-donor substrate obtainable by the method described above comprises a support substrate, a plurality of tiles arranged at a distance from each other on the support substrate, and an interlayer substrate having a plurality of through openings arranged on the support substrate such that each tile is arranged in a respective through opening, a free surface of each tile being flush with the surface of the interlayer substrate.

[0032] According to other advantageous characteristics of said substrate:

[0033] - a distance between two adjacent blocks is greater than or equal to 1 mm, preferably greater than or equal to 2 mm;

[0034] - a distance between each block and an edge of the respective through opening is less than or equal to 250 pm, preferably less than or equal to 100 pm;

[0035] - the tiles comprise a semiconductor material, such as a III-V material. According to another aspect, the invention provides a method for transferring chips onto a receiving substrate. Said method comprises:

[0036] - the formation of a pseudo-donor substrate by the process as described above,

[0037] - bonding said donor pseudo-substrate to a receiving substrate by means of the blocks, and

[0038] - detaching each tile along the weakening zone so as to transfer each chip onto the receiving substrate.

[0039] BRIEF DESCRIPTION OF THE FIGURES

[0040] Other characteristics and advantages of the invention will emerge from the detailed description which follows, with reference to the appended drawings, in which:

[0041] - Figure 1 illustrates a top view and a sectional view of a donor pseudo-substrate according to one embodiment of the invention;

[0042] - Figure 2 illustrates a top view and a sectional view of an interlayer substrate used in the pseudo-donor substrate of Figure 1;

[0043] - Figures 3A to 3D illustrate steps of a first embodiment of the method for manufacturing the donor pseudo-substrate, in which the interlayer substrate of Figure 2 is assembled on a support substrate before the installation of the paving stones;

[0044] - Figures 4A to 4E illustrate steps of a second embodiment of the method for manufacturing the donor pseudo-substrate, in which the interlayer substrate of Figure 2 is assembled on the support substrate after the installation of the paving stones;

[0045] - Figure 5 schematically illustrates the formation of a weakening zone in the paving stones;

[0046] - figure 6 schematically illustrates the bonding of the donor pseudo-substrate of figure 5 on a recipient substrate;

[0047] - Figure 7 is a sectional view of a final structure comprising the chips transferred to the receiving substrate.

[0048] For reasons of readability of the figures, the different elements have not necessarily been represented to scale.

[0049] DETAILED DESCRIPTION OF EMBODIMENTS

[0050] The pseudo-donor substrate comprises tiles of a material of interest arranged in through-openings of an interlayer substrate, the tiles and the interlayer substrate extending over a support substrate.

[0051] The set of paving stones and the interlayer substrate have a free surface extending in the same plane parallel to the main surface of the support substrate. In other words, the surface of the paving stones is flush with the surface of the interlayer substrate. The function of the interlayer substrate is to at least partially fill the gaps between the paving stones. Thus, by increasing the coverage rate of the support substrate by the paving stones and the interlayer substrate, the polishing pad can be kept in the plane of the free surface of the paving stones and prevented from being inserted between the paving stones. Rounding of the edge of the paving stones can therefore be avoided or at least minimized.

[0052] The use of such an interlayer substrate is particularly advantageous when the distance between two adjacent paving stones is greater than or equal to 1 mm, and more preferably greater than or equal to 2 mm.

[0053] The size of the openings is chosen according to the size of the paving stones so that the distance between a paving stone and the edge of the through opening in which said paving stone is arranged is less than or equal to 250 μm, preferably less than or equal to 100 μm. Indeed, the polishing pad, even if flexible, cannot be introduced significantly between the paving stone and the interlayer substrate. The polishing action is therefore limited to the free surface of the paving stones and does not cause rounding of the edges of the paving stones.

[0054] Furthermore, such distances between adjacent paving stones and between a paving stone and the edge of the respective through opening allow for sufficient material to be provided between the openings and thus provide sufficient mechanical strength to the interlayer substrate.

[0055] Pavers are usually made of expensive materials and are only available in small sizes. Alternatively, pavers can be made of stacked materials.

[0056] The paving stones may advantageously comprise at least one of said materials:

[0057] - a semiconductor material, such as a III-V material, in particular indium nitride (InN), gallium nitride (GaN), aluminum nitride (AIN), indium arsenide (InAs), gallium arsenide (GaAs), aluminum arsenide (AlAs), indium phosphide (InP), gallium phosphide (GaP) or aluminum phosphide (AlP), or a IV or IV-IV material, in particular germanium or silicon carbide (SiC),

[0058] - a piezoelectric material, such as lithium tantalate (LiTaCL), lithium niobate (LiNbCL), potassium sodium niobate (KxNai-xNbCL or KNN), barium titanate (BaTiCL), quartz, lead zirconate titanate (PZT), a compound of lead magnesium niobate and lead titanate (PMN-PT), zinc oxide (ZnO), aluminum nitride (AIN) or aluminum scandium nitride (AIScN), and / or

[0059] - an electrically insulating material, such as diamond, strontium titanate, yttria zirconia or sapphire.

[0060] Since the interlayer substrate is only intended to fill the gaps between the paving stones, it is made of a material different from that of the paving stones, which is advantageously less expensive than that of the paving stones, and readily available in a large size, typically identical to the size of the support substrate. Preferably, the material of the interlayer substrate is further chosen to exhibit behavior compatible with that of the paving stones during chemical-mechanical polishing and / or during use of the donor pseudo-substrate.

[0061] Thus, for example, the material of the interlayer substrate advantageously has a hardness comparable to that of the material of the paving stones, so as not to cause a gap between the free surface of the paving stones and the interlayer substrate during polishing.

[0062] Furthermore, the material of the interlayer substrate advantageously has a coefficient of thermal expansion close to that of the paving stones, so as not to cause deformation of the support substrate during heat treatments undergone by the donor pseudosubstrate.

[0063] In some embodiments, the interlayer substrate may be silicon or silicon oxide.

[0064] In other embodiments, the interlayer substrate may have a similar composition to the pavers, but a lower quality. For example, the pavers may be made of a single-crystal III-V material and the interlayer substrate of a polycrystalline III-V material.

[0065] Figure 1 illustrates a top view and a sectional view of a donor pseudo-substrate according to one embodiment of the invention.

[0066] The pseudo-donor substrate comprises a support substrate 3 on which blocks 1 and an interlayer substrate 2 are arranged.

[0067] The paving stones 1 are arranged at regular intervals, with a distance dl between the closest edges of two adjacent paving stones. It should be noted, however, that this arrangement of the paving stones is given for illustrative purposes only; thus, the paving stones may possibly have different shapes, or be arranged at different distances from each other. Furthermore, the paving stones are not necessarily square as illustrated in Figure 1, but may have any other shape suitable for the intended use, with or without a straight edge. For example, the paving stones may have a rectangular, circular shape, or any other shape composed of lines and / or curves.

[0068] The distance dl is advantageously greater than or equal to 1 mm, preferably greater than or equal to 2 mm.

[0069] An interlayer substrate 2 is arranged on the support substrate 3 such that each block 1 extends into a through opening 20 of the interlayer substrate 2. Thus, the interlayer substrate forms partitions arranged between the blocks 1, such that the edge of each block is opposite the edge of the opening. There is thus a distance d2 between the edge of a block and the closest edge of an opening, which is much less than the distance dl.

[0070] For example, the distance d2 is less than or equal to 250 pm, preferably less than or equal to 100 pm. In the embodiment of Figure 1, the paving stones have four rectilinear edges, and the openings of the interlayer substrate have four rectilinear edges. The edge of each opening is arranged opposite a respective edge of the paving stone, parallel to it in order to have a constant distance d2 between the paving stone and the interlayer substrate. Thus, at any point on the perimeter of the paving stone, the distance with the interlayer substrate is at most equal to d2. The remaining free space between the paving stones is then sufficiently restricted to prevent the polishing pad from being inserted between the paving stones and eroding the edges of the paving stones.

[0071] For example, 1 blocks may be 12 mm in size 2 and be spaced by a distance dl equal to 3 mm. The openings 20 then advantageously have a size of 15.75 mm 2, so that the distance d2 between a paving stone and the edge of the interlayer substrate is equal to 0.25 mm.

[0072] To form the donor pseudo-substrate, the interlayer substrate can be assembled on the support substrate before or after the tiles, as will be described below with reference to Figures 3 and 4.

[0073] Figure 2 illustrates the interlayer substrate of Figure 1.

[0074] The intermediate substrate 2 is in the form of a flat plate of the same dimensions as the support substrate 3. For example, the intermediate substrate and the support substrate have a diameter greater than or equal to 150 mm, preferably greater than or equal to 200 mm, and more preferably greater than or equal to 300 mm.

[0075] The interlayer substrate 2 preferably has a thickness e2 (in a direction perpendicular to the plane of said substrate) substantially equal to the thickness el of the paving stones (see FIGS. 3B and 4A) so that, after assembly of the paving stones and the interlayer substrate on the support substrate, the free surface of the paving stones is flush with the free surface of the interlayer substrate. The thickness of the interlayer substrate may optionally be slightly less than the thickness of the paving stones, the flush being able to be obtained by planarization or chemical-mechanical polishing of the paving stones after assembly of the paving stones and the interlayer substrate on the support substrate. For example, the paving stones may have a thickness greater than 5 to 10 μm compared to the thickness of the interlayer substrate.

[0076] Typically, the thickness of the paving stones is in the order of 300 to 650 pm depending on the thickness of the donor material. The thickness of the interlayer substrate is therefore in the order of 300 to 650 pm + / - 5 to 10 pm.

[0077] The interlayer substrate 2 has a plurality of openings 20 distributed according to the pattern provided for the arrangement of the blocks on the support substrate. In the example illustrated, the openings have an identical shape and are distributed regularly in the form of rows and columns, but any other arrangement would be possible. Preferably, the minimum distance between two openings is greater than or equal to 1000 μm so as not to weaken the interlayer substrate and to allow its handling. Each opening has a size slightly larger than the size of the blocks so as to allow each block to be placed in a respective opening with a distance d2 between the edge of the block and the opening sufficiently small to prevent the insertion of the polishing pad into the gap. The width L20 of the opening can therefore be defined as equal to dl-Ll-2xd2, where L1 is the width of a block (see FIG. 4A).

[0078] The interlayer substrate can be manufactured by different techniques.

[0079] According to a first embodiment, the interlayer substrate is formed from a plate in which the openings are cut by laser, water jet or any other technique adapted to the material of the plate and the size of the openings. Particularly advantageously, said plate is a silicon or silicon oxide plate.

[0080] According to a second embodiment, the interlayer substrate is formed by additive manufacturing. For example, from a digital model of the interlayer substrate, which can be obtained by computer-aided design, an additive manufacturing machine is controlled in which a powder is deposited on a support in the form of an elementary layer, a laser scans the surface of the layer to melt the powder except at the location of the openings, then a new elementary layer of powder is deposited on the previously treated elementary layer. Once the desired thickness for the interlayer substrate has been obtained, the substrate is removed from the support and the powder that has not been melted is removed to free the openings. Particularly advantageously, the powder can be made of the same material as the blocks, for example indium phosphide.

[0081] Other additive manufacturing processes, such as stereolithography or filament fusion, can be used to form an interlayer substrate in other materials.

[0082] According to a third embodiment, the intercalary substrate can be manufactured from a semiconductor-on-insulator type structure. Said structure comprises a stack of a silicon substrate or another semiconductor material intended to form the intercalary substrate, a dielectric layer and a handling substrate serving as a mechanical support, for example a silicon substrate. Anisotropic etching of the intercalary substrate is carried out localized at the openings to be formed, the dielectric layer serving as an etching stop layer. The intercalary substrate can then be detached from the handling substrate, for example by selective etching.

[0083] Naturally, a person skilled in the art may use any other suitable method depending on the size of the openings to form an interlayer substrate having appropriate mechanical strength.

[0084] As indicated above, the interlayer substrate is assembled to the support substrate before (see Figures 3A to 3C) or after (see Figures 4A to 4C) the paving stones. Figure 3A schematically illustrates the assembly of the interlayer substrate 2 on the support substrate 3 before the assembly of the paving stones.

[0085] The assembly of the interlayer substrate can be carried out by direct bonding to the support substrate, or by means of an adhesive layer (not shown). Said bonding is advantageously carried out in such a way as to subsequently allow disassembly of the interlayer substrate independently of the paving stones.

[0086] To facilitate the alignment of the paving stones and the openings in the interlayer substrate, it is advantageous to first assemble the paving stones on a temporary support and then transfer said paving stones from the temporary support to the support substrate covered with the interlayer substrate.

[0087] Figure 3B illustrates the placement of the paving stones 1 on a temporary support 4.

[0088] The temporary support is for example formed from one of the following materials: adhesive tape held by a frame, silicon substrate, glass substrate (non-limiting list).

[0089] The pavers may be cut from one or more respective donor substrates and placed on the temporary support using a robot (a technique known as "Pick and Place"). Advantageously, the pavers have the same thickness as the respective donor substrate.

[0090] Referring to Figure 3C, the paving stones 1 are bonded to the support substrate 3 via their free surface through the openings 20 of the intermediate substrate 2, then the temporary support is removed so as to expose the opposite surface of the paving stones. Advantageously, the bonding of the paving stones to the support substrate is direct, but it is possible to use a bonding layer between the paving stones and the support substrate.

[0091] Alternatively, it is possible to assemble the pavers directly onto the support substrate with sufficient precision using the robot by using alignment marks placed on the support substrate. This avoids the use of the temporary support and the transfer of the pavers from the temporary support to the support.

[0092] With reference to Figure 3D, a chemical-mechanical polishing of the free surface of the paving stones 1 and the interlayer substrate 2 is carried out. As shown schematically, due to the small distance between the paving stones and the edge of the openings of the interlayer substrate, the polishing pad 5 acts essentially in the plane of the free surface of the paving stones, without inserting itself between the paving stones. Consequently, the edges of the paving stones remain straight (not rounded).

[0093] Optionally, this chemical-mechanical polishing may be preceded by a step of planarization of the paving stones by mechanical abrasion (“grinding”). Such planarization may be advantageous in particular when the paving stones have different thicknesses, in order to bring their free surface substantially into the same plane, or to reduce the thickness of the paving stones, for example if it is greater than the thickness of the interlayer substrate. However, if the paving stones have coplanar free surfaces, it is possible to dispense with such planarization and to implement the chemical-mechanical polishing directly. Optionally, before the chemical-mechanical polishing, a layer of resin or polymer (not shown) may be deposited between the paving stones and the interlayer substrate, so as to fill the gaps between said paving stones and the interlayer substrate.

[0094] Typically, such a resin or polymer has a large difference in thermal expansion coefficient compared to that of the paving stones and the supporting substrate. Therefore, using this material alone to fill the gap between the paving stones (in the absence of the interlayer substrate) would lead to significant deformation of the assembly during heat treatments. On the other hand, the interlayer substrate allows the quantity of resin or polymer to be used to be minimized and thus reduces the risk of deformation of the assembly.

[0095] Figures 4A to 4E schematically illustrate a variant of the donor pseudo-substrate manufacturing process, in which the assembly of the blocks is carried out on the support substrate before the assembly of the interlayer substrate.

[0096] To facilitate the alignment of the paving stones and the openings in the intermediate substrate, it is advantageous to first assemble the paving stones on a temporary support and then transfer said paving stones from the temporary support to the support substrate.

[0097] Figure 4A illustrates the placement of the paving stones 1 on a temporary support 4.

[0098] The temporary support is for example formed from one of the following materials: adhesive tape held by a frame, silicon substrate, glass substrate (non-limiting list).

[0099] The pavers may be cut from one or more respective donor substrates and placed on the temporary support using a robot (a technique known as "Pick and Place"). Advantageously, the pavers have the same thickness as the respective donor substrate.

[0100] Referring to Figure 4B, the paving stones 1 are bonded to the support substrate 3 via their free surface, then the temporary support is removed so as to expose the opposite surface of the paving stones (see Figure 4C). Advantageously, the bonding of the paving stones to the support substrate is direct, but it is possible to use a bonding layer between the paving stones and the support substrate.

[0101] Alternatively, it is possible to assemble the pavers directly onto the support substrate with sufficient precision using the robot by using alignment marks placed on the support substrate. This avoids the use of the temporary support and the transfer of the pavers from the temporary support to the support.

[0102] With reference to FIG. 4D, the interlayer substrate 2 is assembled on the support substrate 3 so that each opening 20 surrounds a respective block 1.

[0103] The assembly of the interlayer substrate can be carried out by direct bonding to the support substrate, or by means of an adhesive layer (not illustrated). Said bonding is advantageously carried out so as to subsequently allow disassembly of the interlayer substrate independently of the paving stones. With reference to FIG. 4E, a chemical-mechanical polishing of the free surface of the paving stones 1 and of the interlayer substrate 2 is carried out. As shown schematically, due to the small distance between the paving stones and the edge of the openings of the interlayer substrate, the polishing pad 5 acts essentially in the plane of the free surface of the paving stones, without being inserted between the paving stones. Consequently, the edges of the paving stones remain straight (not rounded).

[0104] Optionally, this chemical-mechanical polishing may be preceded by a step of planarization of the paving stones by mechanical abrasion (“grinding”). Such planarization may be advantageous in particular when the paving stones have different thicknesses, in order to bring their free surface substantially into the same plane, or to reduce the thickness of the paving stones, for example if it is greater than the thickness of the interlayer substrate. However, if the paving stones have coplanar free surfaces, it is possible to dispense with such planarization and to implement chemical-mechanical polishing directly.

[0105] Optionally, before chemical-mechanical polishing, a layer of resin or polymer (not shown) can be deposited between the paving stones and the interlayer substrate, so as to fill the gaps between said paving stones and the interlayer substrate.

[0106] Typically, such a resin or polymer has a large difference in thermal expansion coefficient compared to that of the paving stones and the supporting substrate. Therefore, using this material alone to fill the gap between the paving stones (in the absence of the interlayer substrate) would lead to significant deformation of the assembly during heat treatments. On the other hand, the interlayer substrate allows the quantity of resin or polymer to be used to be minimized and thus reduces the risk of deformation of the assembly.

[0107] Particularly advantageously, the interlayer substrate is removed from the support substrate after the implementation of the chemical-mechanical polishing shown schematically in Figures 3D and 4E. Different techniques can be implemented for this removal, depending on the materials concerned and the method of bonding the interlayer substrate to the support substrate. For example, if the interlayer substrate is bonded to the support substrate via an adhesive layer, the removal may include heating the assembly to fluidize the adhesive layer, followed by or combined with a tensile force exerted on the support substrate perpendicular to the main surface of the support substrate, in the direction of moving away from the support substrate. Alternatively, the adhesive layer can be removed or at least degraded by applying a suitable solvent.

[0108] With reference to Figure 5, a weakening zone 10 is formed in the blocks 1, delimiting a surface chip 11 in each block. Said weakening zone is advantageously obtained by implantation of ionic species (for example hydrogen and / or helium), shown diagrammatically by the arrows, in the blocks.

[0109] The formation of the weakening zone is preferably carried out after the chemical-mechanical polishing, but it can optionally be carried out before. In particular, in the case where the paving stones are arranged on the support substrate before the interlayer substrate, it is possible to form the weakening zone in the paving stones before the interlayer substrate is placed on the support substrate to surround the paving stones.

[0110] In some cases, if the intercalator substrate is formed of a material supporting the implantation (e.g., silicon oxide), the implantation can be carried out while the intercalator substrate is in place on the support substrate.

[0111] This produces a pseudo-donor substrate 100 which can subsequently be bonded to a receiving substrate to transfer the chips. The receiving substrate is typically a semiconductor substrate, for example a silicon substrate.

[0112] With reference to Figure 6, the free surface of the paving stones is bonded to the receiving substrate 6. Advantageously, the bonding of the paving stones to the receiving substrate is direct, but it is possible to use a bonding layer between the paving stones and the receiving substrate.

[0113] Referring to Figure 7, the blocks 1 are detached along the weakening zone 10, so as to transfer the chips 11 onto the receiving substrate 6 by the Smart Cut™ process. The detachment can be initiated by a heat treatment, a mechanical and / or chemical action at the weakening zone.

[0114] The chips transferred to the receiving substrate are therefore separated from each other by the distance dl but have non-rounded edges, so that they are functional over their entire surface.

Claims

CLAIMS 1. Method for manufacturing a substrate (100), called a pseudo-donor substrate, comprising a plurality of blocks (1) arranged at a distance from each other on a support substrate (3), comprising: - the arrangement, on the support substrate (3), of said paving stones (1) and of an intermediate substrate (2) made of a material different from that of the paving stones or a material having a composition similar to that of the paving stones but of a lower quality, said intermediate substrate comprising a plurality of through openings (20), so that each paving stone (1) extends into a respective through opening (20) of the intermediate substrate, and - chemical-mechanical polishing of the blocks (1) arranged in the openings of the interlayer substrate by means of a polishing pad, the blocks and the interlayer substrate being separated by free intervals of a width less than or equal to 250 μm so as to minimize the insertion of the polishing pad between the blocks and the interlayer substrate.

2. Method according to claim 1, in which a distance (dl) between two adjacent blocks (1) is greater than or equal to 1 mm, preferably greater than or equal to 2 mm.

3. Method according to one of claims 1 or 2, wherein a distance (d2) between each block (1) and an edge of the respective through opening (20) is less than or equal to 250 pm, preferably less than or equal to 100 pm.

4. Method according to one of claims 1 to 3, in which the blocks comprise a semiconductor material, such as a III-V material.

5. Method according to one of claims 1 to 4, in which the intermediate substrate (2) is formed by cutting openings (20) through a silicon or silicon oxide substrate, in particular by means of a laser or a water jet.

6. Method according to one of claims 1 to 4, in which the interlayer substrate (2) is formed by an additive manufacturing method.

7. Method according to one of claims 1 to 4, in which the intercalary substrate (2) is formed from a semiconductor substrate bonded to a handling substrate via a dielectric layer, the openings being formed by selective etching of the semiconductor material down to the dielectric layer.

8. Method according to one of claims 1 to 7, in which the intermediate substrate (2) has a thickness (e2) less than or equal to the thickness (el) of the blocks (1).

9. Method according to one of claims 1 to 8, comprising, after the implementation of the chemical-mechanical polishing, a removal of the interlayer substrate (2).

10. Method according to one of claims 1 to 9, comprising the formation of a weakening zone (10) in the blocks, so as to delimit in each block a respective chip (11).

11. Method according to one of claims 1 to 10, in which the paving stones (1) are arranged on the support substrate (3) before the intermediate substrate (2).

12. Method according to one of claims 1 to 10, in which the intermediate substrate (2) is arranged on the support substrate (3) before the paving stones (1).

13. Method for transferring chips (11) onto a receiving substrate (6), comprising: - the formation of a pseudo-donor substrate (100) by the method according to claim 10, - bonding said donor pseudo-substrate (100) to a receiving substrate (6) via the blocks (1), and - detaching each block (1) along the weakening zone (10) so as to transfer each chip (11) onto the receiving substrate (6).

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