METHOD FOR PRODUCING A STRUCTURE WITH AT LEAST TWO CHIPS ON A SUBSTRATE

Description

DOMAINE TECHNIQUE

[0001] The invention relates to a method for manufacturing a structure comprising at least two chips on a substrate. ETAT DE LA TECHNIQUE

[0002] In the field of microelectronics, optics or optoelectronics, the design of multilayer structures sometimes requires transferring blocks in the form of portions of a layer from a donor substrate onto a recipient substrate.

[0003] This type of process is generally called a paving process, and involves a partial transfer of a layer taken from the donor substrate to form one or more paving stones arranged according to a pattern or at a predetermined location on the receiving substrate.

[0004] Such tiling may be necessary due to a size difference between the donor and recipient substrates. Indeed, because of this size difference, it is not possible to transfer an entire layer from the donor substrate to the recipient substrate.

[0005] A well-known layer transfer method is the Smart Cut™ process, in which a weakened zone is created by implanting atomic species into the donor substrate, delimiting the layer to be transferred. The donor substrate is then bonded to the recipient substrate, and the donor substrate is detached along the weakened zone to transfer the layer from the donor substrate to the recipient substrate. However, this process assumes that the donor and recipient substrates are of identical size.

[0006] However, while silicon substrates are available in relatively large sizes, typically with a diameter of 300 mm, other materials of interest currently exist only as smaller, bulk substrates, 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 generated during transfer.This is particularly the case for III-V semiconductor materials, including nitrides (for example, in the case of binary compounds, indium nitride (InN), gallium nitride (GaN) and aluminium nitride (AlN)), arsenides (for example, in the case of binary compounds, indium arsenide (InAs), gallium arsenide (GaAs) and aluminium arsenide (AlAs)), and phosphides (for example, in the case of binary compounds, indium phosphide (InP), gallium phosphide (GaP) and aluminium phosphide (AlP)).

[0007] Instead of transferring an entire layer of the donor substrate, a solution based on the Smart Cut™ process involves creating an intermediate substrate, known as a pseudo-donor, by taking one or more blocks from at least one donor substrate and transferring these blocks onto a support substrate with the same diameter as the recipient substrate. The process then includes creating a weakened zone in each block by implanting atomic species, bonding the pseudo-donor substrate to the recipient substrate via the blocks, and detaching each block along the weakened zone to transfer a portion of each block onto the recipient substrate.

[0008] During the process, it is generally necessary to polish the paving stones after the pseudo-donor substrate has been formed and / or after the paving stone sections have been transferred to the receiving substrate. This polishing, which is typically chemical mechanical polishing (CMP), aims to flatten the free surface of the paving stones or sections of paving stones.

[0009] A particular difficulty arises when the paving is sparse, meaning that the coverage rate of the pavers on the receiving substrate, which corresponds to the ratio between the total surface area of ​​the pavers and the total surface area of ​​the receiving substrate, is typically less than 50%, or even less than 30%. In this situation, il There is a significant distance, typically on the order of a few millimeters, between the paving stones on the pseudo-donor substrate and on the receiving substrate.

[0010] However, the polishing cloth applied to the paving stones is prone to deformation in the hollows formed by the spaces between the stones. This deformation leads to differences in polishing height between paving stones and excessive material consumption at the edges of the paving stones compared to their centers.

[0011] These inhomogeneities generated by polishing penalize the subsequent use of the blocks to form electronic, optical or opto-electronic components.

[0012] US 2020 / 366064 A1 discloses a method for manufacturing a structure comprising at least two chips on a receiving substrate. BREVE DESCRIPTION DE L'INVENTION

[0013] One object of the invention is to design a method for manufacturing a structure comprising at least two chips on a support substrate, which makes it possible to remedy the aforementioned polishing defects.

[0014] To this end, the invention proposes a method for manufacturing a structure comprising at least two chips on a receiving substrate, comprising: the formation of a pseudo-donor substrate by placing at least one block of at least one donor substrate on a support substrate; the bonding of said pseudo-donor substrate to a receiving substrate via the blocks so that each block covers at least partially at least two distinct areas of interest of the receiving substrate; the transfer of a portion of said blocks onto the receiving substrate; at least one mechano-chemical polishing step of the blocks of the pseudo-donor substrate and / or the portions of blocks transferred onto the receiving substrate; after said at least one mechano-chemical polishing step, a removal of material from said portions of blocks so as to divide each portion of block into at least two chips arranged each on a respective area of ​​interest.

[0015] Resizing the paving stone portions after their transfer to the receiving substrate to form the chips increases the paving stone density on the pseudo-donor substrate and reduces the distances between paving stones and, after transfer, between paving stone portions. Consequently, polishing defects related to excessive distances between paving stones or between transferred paving stone portions are minimized.

[0016] After the etching stage, the coverage rate of the chips on the receiving substrate, i.e. the ratio between the total surface area of ​​the chips and the total surface area of ​​the receiving substrate, is advantageously less than 50%, preferably less than 30%.

[0017] Particularly advantageously, the coverage rate of the paving stones on the pseudo-donor substrate, i.e. the ratio between the total surface area of ​​the paving stones and the total surface area of ​​the supporting substrate, is greater than 50%, preferably greater than 75%.

[0018] Each paving stone may have a side length greater than or equal to 5 mm, preferably greater than or equal to 8 mm, and preferably greater than or equal to 10 mm.

[0019] Furthermore, each chip may have one side of length less than or equal to 5 mm, preferably less than or equal to 3 mm, and preferably less than or equal to 1 mm.

[0020] Particularly advantageously, the distance between two adjacent paving stones is less than or equal to 3 mm, preferably less than or equal to 1 mm.

[0021] The distance between two adjacent chips can, however, be greater than or equal to 3 mm, preferably greater than or equal to 5 mm.

[0022] In some embodiments, each tile covers at least partially two distinct areas of interest of the receiving substrate and a chip is formed from said tile on each respective area of ​​interest.

[0023] In other embodiments, each tile covers a respective corner of four distinct areas of interest of the receiving substrate arranged in a square or rectangle, and a chip is formed from said tile on each corner of the respective area of ​​interest.

[0024] In other embodiments, each tile is in the form of a strip covering at least partially at least three aligned areas of interest of the receiving substrate and a chip is formed from said tile on each respective area of ​​interest.

[0025] In a particularly advantageous way, the support substrate and the receiving substrate have a diameter that is substantially the same, greater than the diameter of the donor substrate.

[0026] The bonding of the pseudo-donor substrate to the recipient substrate can be achieved by molecular adhesion.

[0027] In a preferred embodiment, the transfer of each portion of the paving successively includes the formation of a weakening zone by implanting atomic species in each paving of the pseudo-donor substrate to define a portion of the paving to be transferred, the bonding of the pseudo-donor substrate to the receiving substrate via the paving, and the detachment of each paving along the weakening zone.

[0028] In other embodiments, the transfer of each portion of the paving stone includes thinning by grinding and / or engraving each paving stone from the pseudo-donor substrate.

[0029] Each block can have a thickness between 20 µm and 1000 µm, preferably between 100 µm and 700 µm, and the transferred portion of each block can have a thickness between 30 nm and 1.5 µm.

[0030] Each brick may include: a semiconductor material, such as a III-V material, including 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, including germanium or silicon carbide (SiC); a piezoelectric material, such as lithium tantalate (LiTaO3), lithium niobate (LiNbO3), potassium-sodium niobate (KxNa1-xNbO3 or KNN), barium titanate (BaTiO3), quartz, or lead zirconate titanate (PZT), a lead-magnesium niobate and lead titanate compound (PMN-PT), zinc oxide (ZnO), aluminium nitride (AIN) or aluminium scandium nitride (AIScN), and / or an electrically insulating material, such as diamond, strontium titanate, yttria zirconia or sapphire.

[0031] In some embodiments, the process includes an epitaxial formation step of at least one epitaxial layer on each portion of the paving stone, with material removal to divide each portion of the paving stone into chips being carried out after said epitaxial step.

[0032] In some embodiments, material removal includes: the formation of a mask comprising a protective film partially covering said portions of blocks according to a pattern defining said chips in each portion of block and at least one opening defining a space to be formed between two chips; the engraving of each portion of block through each opening of the mask so as to form said space to separate said chips from each other.

[0033] The engraving can be carried out using an etching solution and the mask is made of a photosensitive resin.

[0034] Alternatively, the engraving can be carried out using an ion beam and the mask is formed from a metal.

[0035] In other embodiments, material removal is carried out selectively by a focused beam of ions, said beam being controlled to scan only the regions of the portions of paving stones to be removed. BREVE DESCRIPTION DES FIGURES

[0036] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the attached drawings, in which: there figure 1 is a top view of the receiving substrate on which the areas of interest are schematically represented, the figure 2 illustrates a step in the extraction of paving stones from a donor substrate, the figure 3 illustrates a step in placing said paving stones on a support substrate to form a pseudo-donor substrate, the figure 4 illustrates a stage in the formation of a weakened zone within the said paving stones, the figure 5 illustrates a step of bonding the pseudo-donor substrate to a recipient substrate via the paving stones, the figure 6 illustrates a step in transferring portions of paving stones onto the second supporting substrate following the detachment of the paving stones along the weakened area, the figure 7 illustrates a step in the formation of a mask on the portions of the tiles in order to delimit the chips to be formed, the figure 8 illustrates a step in etching the areas of the paving stones not protected by the mask to form the chips, the figure 9 illustrates a step in removing the protective film after engraving, the figure 10A illustrates an embodiment in which each tile partially covers two adjacent areas of interest, and the figure 10B illustrates an example of the distribution of chips formed from said tiles, the figure 11A illustrates an embodiment in which each block partially covers several aligned areas of interest, and the figure 11B illustrates an example of the distribution of chips formed from said tiles, the figure 12A illustrates an embodiment in which each tile partially covers four areas of interest arranged in a square, and the figure 12B illustrates an example of the distribution of chips formed from said tiles.

[0037] For readability, the drawings are not necessarily to scale. Furthermore, the number and shape of the areas of interest, blocks, and bullet points shown in the drawings are for illustrative purposes only. DESCRIPTION DETAILLEE DE MODES DE REALISATION

[0038] The invention proposes forming a structure comprising at least two chips on a receiving substrate, in which polishing inhomogeneities are avoided even when the chips are spaced relatively far apart and / or distributed sparsely on the receiving substrate. This is achieved by using a pseudo-donor substrate comprising blocks, each designed to form at least two chips, said chips being distributed over at least two distinct areas of interest on the receiving substrate. The pseudo-donor substrate is bonded to the receiving substrate via the blocks, so as to transfer a portion of the blocks onto the receiving substrate. Then, material removal from each block, particularly between the chips, allows each chip to be formed.

[0039] By low density, we mean in this text that the coverage rate of the chips on the receiving substrate, which corresponds to the ratio between the total surface area of ​​the chips and the total surface area of ​​the receiving substrate, is typically less than 50%, or even less than 30%, and / or that the distance between two adjacent chips is greater than or equal to 3 mm, or even greater than or equal to 5 mm.

[0040] In this text, an area of ​​interest is defined as a region of the receiving substrate intended to subsequently form an electronic circuit distinct from the electronic circuit formed in an adjacent region. Specifically, in a later manufacturing step of these electronic circuits, the receiving substrate may be cut to form individual chips.

[0041] The areas of interest are not necessarily visible on the receiving substrate; they can, in particular, be defined on a plane indicating the location of each component on the receiving substrate at each stage of the manufacturing process. The location of the areas of interest on the receiving substrate is related to this plane by means of a reference frame of the receiving substrate, that is, a coordinate system attached to the receiving substrate, which allows the position of each point on the surface of the receiving substrate to be defined. For example, this reference frame may include an origin point located on an edge of the receiving substrate, such as a notch commonly used in the semiconductor industry, and two orthogonal axes extending in the plane of the substrate, one of the axes extending diametrically from the notch and the other intersecting the first axis at the center of the substrate.

[0042] There figure 1 This illustrates an example of the distribution of areas of interest on a receiving substrate. The receiving substrate 3 has a plurality of areas of interest Z1, Z2, Zn (n being an integer between 1 and the total number of areas of interest) delimited by dashed lines. These areas are not necessarily physically present on the surface of the receiving substrate, but the location of each area of ​​interest in a reference frame of the receiving substrate is known.

[0043] In the example shown on the figure 1 The areas of interest all have the same rectangular shape and are arranged on the receiving substrate in rows and columns to form a grid. However, in other, unillustrated embodiments, the areas of interest may have different dimensions and / or shapes.

[0044] The transfer process involves at least one mechano-chemical polishing of the paving stones. Such polishing can be carried out after the paving stones have been placed on the support substrate to form the pseudo-donor substrate, before bonding to the receiving substrate, on the portions of paving stones transferred to the receiving substrate, or even on both the paving stones of the pseudo-donor substrate and on the portions of paving stones transferred to the receiving substrate.

[0045] The fact that the tiles are sized to form at least two chips allows the coverage rate of the tiles to be increased and / or the distance between tiles to be decreased on the pseudo-donor substrate compared respectively to the coverage rate of the chips on the receiving substrate, and the spacing between chips.

[0046] Thus, the paving stone coverage ratio on the pseudo-donor substrate—that is, the ratio between the total surface area of ​​the paving stones and the total surface area of ​​the supporting substrate—is advantageously greater than 50%, and preferably greater than 75%. The receiving substrate may have a diameter substantially identical to that of the supporting substrate. In this case, this coverage ratio will also apply to the portions of paving stones transferred onto the receiving substrate.

[0047] Advantageously, the distance between two adjacent paving stones is less than or equal to 3 mm, preferably less than or equal to 1 mm.

[0048] Furthermore, the pseudo-donor and recipient substrates can be in the form of a fairly thin disk typically a few hundred µm thick (commonly called a "slice" in the field of microelectronics) or a rectangular shape or any geometric shape.

[0049] Consequently, the paving stones (and the transferred portions of paving stones) are advantageously distributed with sufficient density to prevent inhomogeneity in thickness between paving stones or transferred portions of paving stones. Indeed, deformation of the polishing material between adjacent paving stones is minimized, resulting in a substantially uniform polish across the entire surface of the paving stones or portions of paving stones.

[0050] Only after this polishing step are the chips formed by removing material from the portions of the blocks transferred to the receiving substrate. This material removal leads to a reduction in chip density compared to that of the blocks, but since no further mechano-chemical polishing of the chips is required, it does not pose a risk of loss of homogeneity in chip thickness and shape.

[0051] Material removal can be achieved through various techniques, which are known in themselves.

[0052] Some techniques use a mask to protect the surface of the chips and expose the surface of the portions of the chips intended to be removed by applying an etching agent.

[0053] A particularly advantageous feature is that the mask is formed by photolithography, with the protective film consisting of a photosensitive resin resistant to the etching agent, which is a chemical etching compound. Because photolithography is highly precise, it ensures that the chips have the desired shape and position.

[0054] Alternatively, the etching agent is an ion beam (a technique known as "sputtering"). The mask may include a metallic protective film or a photosensitive resin, which protects the material from the ion beam in the areas covered by the protective film.

[0055] The mask is removed after the sections of paving stones have been engraved over all or part of their thickness.

[0056] It should be noted that it is possible to do without the use of a mask if a selective etching process is used which employs a focused beam of controlled etching ions to scan only the areas of the portions of paving stones to be removed.

[0057] The pseudo-donor substrate can be made by placing the paving stones one by one, or in small groups of paving stones, on the support substrate, for example by the "Pick and Place" process; on the other hand, the transfer of the paving stones from the pseudo-donor substrate to the receiving substrate can be carried out simultaneously.

[0058] The process thus allows a block of material to be subdivided into several smaller chips, extending over several distinct, preferably adjacent, areas of interest. The process therefore offers the advantage of forming very small chips without having to place them individually on the receiving substrate, and by avoiding the problems of inhomogeneity due to chemical polishing if the chips are sparsely distributed.

[0059] For example, each paving stone initially has a side length greater than or equal to 5 mm, preferably greater than or equal to 8 mm, and preferably greater than or equal to 10 mm.

[0060] Advantageously, the paving stones are made of a material that is not commercially available as a large-format donor substrate. Thus, the donor substrate can have a diameter of less than 30 cm, for example, on the order of 10 or 15 cm.

[0061] This is particularly the case for III-V semiconductor materials, including nitrides (for example, in the case of binary compounds, indium nitride (InN), gallium nitride (GaN) and aluminium nitride (AlN)), arsenides (for example, in the case of binary compounds, indium arsenide (InAs), gallium arsenide (GaAs) and aluminium arsenide (AlAs)), and phosphides (for example, in the case of binary compounds, indium phosphide (InP), gallium phosphide (GaP) and aluminium phosphide (AlP)).

[0062] This is also the case for IV or IV-IV semiconductor compounds, such as germanium and silicon carbide.

[0063] The paving stones can also be made of a piezoelectric material, for example lithium tantalate (LiTaO3) or lithium niobate (LiNbO3), potassium-sodium niobate (KxNa1-xNbO3 or KNN), barium titanate (BaTiO3), quartz, lead zirconate titanate (PZT), a lead-magnesium niobate and lead titanate compound (PMN-PT), zinc oxide (ZnO), aluminium nitride (AIN) or aluminium-scandium nitride (AlScN) (non-exhaustive list).

[0064] Paving stones can also be made of an electrically insulating material, such as diamond, strontium titanate (SrTiO3), yttria zirconia (YSZ), or sapphire.

[0065] THE figures 2 à 9 schematically illustrate the formation of a pseudo-donor substrate comprising the tiles placed on a first support substrate and the transfer of the tile portions onto a receiving substrate, then the division of each tile portion into at least two chips.

[0066] With reference to the figure 2 P1-P3 blocks are cut from a donor substrate 2. The blocks can be cut using any technique known to those skilled in the art. This can include sawing and / or cleaving, or laser cutting. It can also, for example, be combined with a partial plasma etching step of the cut lines, a technique known as "plasma dicking".

[0067] There figure 3 illustrates the placement of the paving stones taken from the donor substrate of the figure 2 on a support substrate 1 to form a pseudo-donor substrate 10.

[0068] The placement can be implemented by the "Pick and Place" technique, whereby a robot picks up a block, or a group of blocks, previously cut from the donor substrate and places it at a predetermined location on the support substrate.

[0069] In some embodiments, each paver adheres to the substrate by molecular adhesion. To this end, surface treatments of the pavers and / or the substrate may be applied beforehand to promote good molecular adhesion. These treatments may include, in particular, cleaning, the application of an adhesive layer such as silicon dioxide (SiO2), plasma activation prior to bonding, and annealing.

[0070] In other embodiments (not illustrated), the bonding of the paving stones to the supporting substrate may involve an intermediate bonding layer, for example a polymer bonding layer, a eutectic bonding layer or a ceramic adhesive layer.

[0071] The support substrate 1 advantageously has a diameter or dimensions greater than those of the donor substrate 2. For example, the support substrate 1 may have the shape of a disc with a diameter of approximately 300 mm.

[0072] There figure 4 This illustrates the formation of a weakening zone in the P1-P3 blocks in order to delimit a surface portion of said blocks intended to be transferred onto a receiving substrate. As shown schematically by the arrows, the weakening zone 11 is advantageously formed by implanting atomic species, such as hydrogen and / or helium, into the blocks, at a depth corresponding to the thickness of the layer to be transferred.

[0073] Optionally, the pseudo-donor substrate can be subjected to mechano-chemical polishing of the paving stone surface.

[0074] There figure 5 illustrates the bonding of the pseudo-donor substrate of the figure 3 on a receiving substrate via the paving stones.

[0075] During this bonding, the two substrates are positioned relative to each other in such a way that each block of the pseudo-donor substrate 10 covers at least partially at least two distinct areas of interest of the receiving substrate 3.

[0076] In the illustrated example, each pad partially covers four areas of interest arranged in a square or rectangle. This means that the four areas of interest lie in two adjacent rows and two adjacent columns, with the centers of the four areas of interest forming the four vertices of the square or rectangle. Each pad therefore covers not only a portion of the area of ​​these areas of interest but also the surface of the receiving substrate located between the areas of interest, which, in this example, has a cross shape. Generally, to optimize the surface area of ​​the receiving substrate and minimize material waste, the distance between areas of interest is minimized. The area of ​​each area of ​​interest covered by the pad is adapted according to the size of the components to be formed in or on the chip or the area of ​​interest.

[0077] A particularly advantageous feature is that each paver adheres to the receiving substrate 3 via molecular adhesion. To this end, surface treatments of the paving stones and / or the receiving substrate can be carried out beforehand to promote good molecular adhesion. These treatments may include, in particular, cleaning, the application of an adhesive layer such as silicon dioxide (SiO2), plasma activation prior to bonding, polishing, and annealing, preferably at low temperature (i.e., typically below 300°C).

[0078] The support substrate 1 and the receiving substrate 3 advantageously have a diameter that is substantially identical, for example on the order of 300 mm.

[0079] Next, with reference to the figure 6 , the paving stones are detached along the weakening zone 11, in order to transfer the portions P'1, P'2, P'3 delimited by said weakening zone onto the receiving substrate.

[0080] The paving stones placed on the substrate typically have a thickness between 20 µm and 1000 µm, preferably between 100 µm and 700 µm. The transferred portion of each paving stone generally has a thickness between 30 nm and 1.5 µm.

[0081] According to an alternative to the Smart Cut™ process described above, the paving stone sections can be obtained by thinning each stone of the pseudo-donor substrate through grinding and / or engraving after the pseudo-donor substrate has been bonded to the receiving substrate. However, an advantage of the Smart Cut™ process is that it minimizes material loss, as the pseudo-donor substrate can potentially be recycled and used to transfer paving stone sections back onto the same receiving substrate or a different one.

[0082] Optionally, after transferring said portions of paving stones onto the receiving substrate, a mechano-chemical polishing of the surface of the portions of paving stones can be implemented.

[0083] There figure 7 illustrates the formation, for example by photolithography, of a mask comprising a protective film M11, M12, M13, M14 partially covering each portion of the block and openings extending between the portions of the protective film.

[0084] The protective film is configured to define a pattern corresponding to the geometry and location of each chip on each respective area of ​​interest.

[0085] The openings typically correspond to the surface of the receiving substrate located between the areas of interest. Thus, in the illustrated example, the openings are cross-shaped and delimit four rectangular portions M11-M14 of the protective film on each paving stone section.

[0086] In one embodiment, the protective film does not extend to the edges of the paving stone portion located in the area of ​​interest. This allows, in the subsequent engraving step, for the removal of a peripheral region of the paving stone portions, for example, to resize said portion. However, in order to minimize material loss, the paving stones are preferably sized to minimize the peripheral region to be removed.

[0087] The film can be made of any suitable resin. Particularly in the field of microelectronics, such photosensitive resins, marketed for example by companies like Shipley or AZ Electronic Materials, are dispensed in a viscous state and spread onto substrates using spin coating machines (a process known as "spin coating") and then annealed. A UV exposure step after development allows the exposed areas to be retained or removed. According to a variant known as "dry film photo resist," these resins can also be applied by laminating a thick film, typically between 15 and 50 µm thick, supplied in rolls.

[0088] With reference to the figure 8 An etching solution is applied to the structure of the figure 7 The composition of the etching solution is chosen according to the paving stone material. For example, if the paving stones are made of InP, wet etching in a bath of hydrochloric acid (HCl) and phosphoric acid (H3PO4) can be used. Plasma etching using halogenated gases (chlorine-based, for example) or methane / dihydrogen mixtures (CH4 / H2) can also be used.

[0089] Advantageously, the etching solution does not attack, or only minimally attacks, the receiving substrate material 3.

[0090] Alternatively, sputtering under an ion beam, such as argon, can also be used. In this case, the protective film is advantageously metallic.

[0091] After the engraving, the part of the tiles not covered by the protective film was removed, over all or part of the thickness of the tiles, to separate the chips.

[0092] With reference to the figure 9 The protective film is removed to expose the surface of the chips. The structure is then ready for subsequent manufacturing steps, such as the deposition or epitaxy of one or more additional layers on the chips, the formation of electronic components in or on the chips, the cutting of the receiving substrate to separate the chips, etc.

[0093] It should be noted that, after chip formation, no chemical polishing is performed to avoid creating inhomogeneity within the chips. In other words, any chemical polishing step is carried out either on the pseudo-donor substrate or on the receiving substrate after the transfer of the wafer portions, but before the material removal process that results in the formation of the chips. Thus, chemical polishing is always performed on the wafers or wafer portions, which are relatively large, exceeding the size required to produce the intended chips. More precisely, each wafer has a dimension greater than a multiple of the target chip size in the manufacturing process. For example, each wafer may have a dimension two or four times larger than the target dimension.

[0094] Multiple geometries can be obtained depending on the destination of the final structure and the arrangement of areas of interest.

[0095] In some embodiments, each tile covers at least partially two distinct areas of interest of the receiving substrate and a chip is formed from said tile on each respective area of ​​interest.

[0096] For example, as illustrated on the figure 10A , each paving stone and transferred paving stone portion P'1 can be arranged so as to cover a part of two adjacent areas of interest as well as the surface of the receiving substrate between said areas of interest. The material removal can be carried out so as to remove the material from each paving stone portion opposite the surface separating the areas of interest, and, where appropriate, the material from each paving stone portion opposite each area of ​​interest to respect the desired geometry for each chip p11, p12 (cf. figure 10B ).

[0097] According to another example, illustrated on the figure 11A , each transferred block and portion of block P'1, P'2, P'n can be presented as an elongated strip partially covering a plurality of aligned areas of interest. We can then form one or more aligned bullets p11, p12, p1n in each of the areas of interest belonging to the same row or column (cf. figure 11B ).

[0098] In other embodiments, as illustrated in the figure 12A , which is an enlargement of the figure 5 , each transferred tile and portion of tile P'1 can be arranged so as to cover a respective corner of four distinct interest zones of the receiving substrate arranged in a square, and from said tile, a chip p11, p12, p13, p14 is formed on each corner of the respective interest zone (cf. figure 12B ).

[0099] Naturally, these different configurations can be combined. For example, it is possible to transfer portions of paving stones oriented differently (for example, perpendicular in pairs) depending on the areas of interest to be covered.

[0100] The process therefore offers great flexibility in the formation of chips depending on the components to be formed. Exemples d'applications

[0101] The present invention presents various particularly advantageous application cases, especially in the field of microelectronics.

[0102] The process allows for the low-density placement of chips on a 300 mm diameter receiving substrate. This receiving substrate can be a silicon substrate or a silicon-on-insulator (SOI) substrate.

[0103] In photonic applications, the active layer of the receiving substrate can include a photonic circuit comprising passive or active devices, for example, one or more waveguides, one or more multiplexers, one or more microresonators, etc. The chips transferred onto this layer can be made of InP, which is a material better suited than silicon for the epitaxial growth of a III-V material stack to form a laser.

[0104] In radio frequency (RF) applications, the active layer of the receiving substrate may include components operating at relatively low frequencies, while the chips, which are advantageously made of InP or GaN, may include components operating at the highest frequencies.

[0105] In micro-LED applications, the size of GaN chips is advantageously less than 50 µm.

Claims

1. Method for manufacturing a structure comprising at least two chips (p11, p12, p13, p14) on a receiving substrate (3), comprising: - forming a pseudo-donor substrate (10) by placing at least one tile (P1, P2, P3) from at least one donor substrate (2) on a support substrate (1); - bonding said pseudo-donor substrate (10) to a receiver substrate (3) via the tiles so that each tile at least partially covers at least two distinct areas of interest (A1, A2, A3) of the recipient substrate (3); - transferring a portion (P'1, P'2, P'3) of said tiles (P1, P2, P3) onto the receiver substrate (3); - at least one step of mechanochemical polishing of the tiles (P1, P2, P3) of the pseudo-donor substrate and / or portions of tiles transferred onto the receiver substrate; - after said at least one step of mechanical-chemical polishing, removing material from said portions (P'1, P'2, P'3) of tiles so as to divide each portion of tile into at least two chips (p11, p12, p13, p14), each arranged on a respective area of interest (Z1, Z2, Zn).

2. Method according to claim 1, wherein, after the etching step, the coverage ratio of the chips (p11, p12, p13, p14) on the receiver substrate (3), i.e., the ratio between the total area of the chips and the total area of the receiver substrate, is less than 50%, preferably less than 30%.

3. Method according to one of claims 1 or 2, wherein the coverage ratio of the tiles (P1, P2, P3) on the pseudo-donor substrate (10), i.e., the ratio between the total area of the tiles and the total area of the support substrate, is greater than 50%, preferably greater than 75%.

4. Method according to one of claims 1 to 3, wherein each tile (P1, P2, P3) has a side length greater than or equal to 5 mm, preferably greater than or equal to 8 mm, and preferably greater than or equal to 10 mm.

5. Method according to one of claims 1 to 4, wherein each chip (p11, p12, p13, p14) has a side length less than or equal to 5 mm, preferably less than or equal to 3 mm, and preferably less than or equal to 1 mm.

6. Method according to one of claims 1 to 5, wherein the distance between two adjacent tiles (P1, P2, P3) is less than or equal to 3 mm, preferably less than or equal to 1 mm.

7. Method according to one of claims 1 to 6, wherein the distance between two adjacent chips (p11, p12, p13, p14) is greater than or equal to 3 mm, preferably greater than or equal to 5 mm.

8. Method according to one of claims 1 to 7, wherein each tile at least partially covers two distinct areas of interest of the receiver substrate and a chip is formed from said tile on each respective area of interest.

9. Method according to one of claims 1 to 7, wherein each tile covers a respective corner of four distinct areas of interest of the receiver substrate arranged in a square or rectangle, and a chip is formed from said tile on each corner of the respective area of interest.

10. Method according to one of claims 1 to 7, wherein each tile is in the form of a strip at least partially covering at least three aligned areas of interest of the receiving substrate, and a chip is formed from said tile on each respective area of interest.

11. Method according to one of claims 1 to 10, wherein the support substrate (1) and the receiver substrate (3) have a substantially identical diameter, greater than the diameter of the donor substrate (2).

12. Method according to one of claims 1 to 11, wherein the pseudo-donor substrate (10) is bonded to the receiver substrate (3) by molecular adhesion.

13. Method according to one of claims 1 to 12, wherein the transfer of each portion (P'1, P'2, P'3) of tile comprises successively forming a weakening zone (11) by implanting atomic species in each tile (P1, P2, P3) of the pseudo-donor substrate (10) to define a portion (P'1, P'2, P'3) of the tile to be transferred, bonding the pseudo-donor substrate (10) to the receiver substrate (3) via the tiles (P1, P2, P3), and detaching each tile along the weakening zone (11).

14. Method according to one of claims 1 to 12, wherein the transfer of each portion (P'1, P'2, P'3) of tile comprises thinning by grinding and / or etching each tile (P1, P2, P3) of the pseudo-donor substrate.

15. Method according to one of claims 1 to 14, wherein each tile (P1, P2, P3) has a thickness between 20 µm and 1000 µm, preferably between 100 µm and 700 µm, and the transferred portion of each tile has a thickness between 30 nm and 1.5 µm.

16. Method according to one of claims 1 to 15, wherein each tile (P1, P2, P3) comprises: - 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, such as germanium or silicon carbide (SiC), - a piezoelectric material, such as lithium tantalate (LiTaO3), lithium niobate (LiNbO3), potassium-sodium niobate (KxNa1-xNbO3 NbO3 or KNN), barium titanate (BaTiO3 ), quartz, lead zirconate titanate (PZT), a lead magnesium niobate-lead titanate compound (PMN-PT), zinc oxide (ZnO), aluminum nitride (AIN) or aluminum scandium nitride (AIScN), and / or - an electrically insulating material, such as diamond, strontium titanate, yttria-stabilized zirconia, or sapphire.

17. Method according to one of claims 1 to 16, comprising a step of forming at least one epitaxial layer on each die portion by epitaxy, wherein the removal of material to divide each tile portion into chips is performed after said epitaxy step.

18. Method according to one of claims 1 to 17, wherein the removal of material comprises: - forming a mask comprising a protective film partially covering said tile portions in a pattern defining said chips in each tile portion and at least one opening defining a space to be formed between two chips; - etching each tile portion through each opening in the mask so as to form said space to separate said chips from each other.

19. Method according to claim 18, wherein the etching is performed using an etching solution and the mask is formed from a photosensitive resin.

20. Method according to claim 18, wherein the etching is performed using an ion beam and the mask is formed from a metal.

21. Method according to one of claims 1 to 17, wherein the removal of material is performed selectively by a focused ion beam, said beam being controlled to scan only the regions of the tile portions to be removed.