Process for manufacturing a structure comprising at least two tiles on a substrate - Patents.com

Abstract

The invention relates to a process comprising: arranging at least two tiles ((P1, P2), (P'1, P'2)) on a supporting substrate (1, 3, S), said tiles being arranged on said supporting substrate (1, 3, S) in an inaccurate distribution and / or geometry compared to a target distribution and / or geometry; forming a mask comprising a protective film (M1, M2) partially covering said tiles ((P1, P2), (P'1, P'2)) in a pattern defining the target distribution and / or geometry and at least one opening extending around the protective film (M1, M2); and etching at least one tile ((P1, P2), (P'1, P'2)) through the opening in the mask so as to modify the arrangement of the tiles according to the target distribution and / or geometry.

Description

[Technical field]

[0001] The present invention relates to a process for manufacturing a structure comprising at least two tiles on a supporting substrate. [Background technology]

[0002] In the fields of microelectronics, optics or optoelectronics, the design of multi-layer structures may require tiles to be transferred to a support or receiver substrate in the form of a portion of a layer of a donor substrate.

[0003] This type of process is commonly referred to as a tiling process and involves the partial transfer of a layer taken from a donor substrate to form one or more tiles arranged in a pattern or at predetermined locations on a supporting substrate.

[0004] Such tiling may be necessitated by differences in size between the donor substrate and the support substrate, in particular, differences in size that do not allow for the transfer of an entire layer of the donor substrate to the support substrate.

[0005] A well-known layer transfer process is the Smart Cut™ process, in which a donor substrate is implanted with atomic species to form weakened zones that define the layer to be transferred, the donor substrate is bonded to a support substrate, and the donor substrate is separated along the weakened zones to transfer the layer from the donor substrate to the support substrate. However, that process assumes that the donor substrate and the support substrate are the same size.

[0006] However, while silicon substrates with relatively large sizes, typically 300 mm diameter, are available, other materials of interest currently exist only in the form of bulk substrates with smaller sizes, for example 10 or 15 cm diameter. Furthermore, these materials of interest can be particularly expensive, and it is therefore desirable to minimize potential waste formed during transfer. This is especially true for semiconductor materials III-V, including nitrides (e.g., for binary compounds, indium nitride (InN), gallium nitride (GaN) and aluminum nitride (AlN)), 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)).

[0007] Instead of transferring the entire layer of the donor substrate, the solution based on the Smart Cut™ process consists in taking one or more tiles from at least one donor substrate and transferring said tiles to a first substrate to form what is known as a pseudo donor substrate, forming a weakened zone in each tile by implanting atomic species, bonding the pseudo donor substrate to a second substrate via the tiles, and separating each tile along the weakened zone so as to transfer a portion of each tile to the second substrate, the first substrate and the second substrate being of the same size.

[0008] 1 shows a top view and a cross-sectional view of a support substrate S on which a number of tiles P1-P9 from at least one donor substrate are arranged. In this example, there are nine tiles distributed in three rows and three columns.

[0009] The structures may be manufactured using a "pick and place" technique, in which the at least one donor substrate is cut into tiles, and each tile is then placed onto the surface of a support substrate with the aid of a robot.

[0010] However, because each tile is transferred individually to the first substrate, this technique can be very slow, especially due to the precision required to align the tiles. The precision of the robot may even be less than the precision required to place and orient the tiles. Thus, tile positioning errors relative to the reference frame of the support substrate and / or tile alignment errors relative to each other are observed.

[0011] An example of such an error is shown in Figures 2A and 2B, which show four tiles P1-P4 arranged in two rows (oriented along the horizontal direction in these figures) and two columns (oriented along the vertical direction in these figures). In Figure 2A, tile P4 is vertically spaced a distance d from tile P3 in the adjacent column. 1 and is offset horizontally by a distance d 2 It can be seen that tile P4 is offset by an angle α relative to the vertical, such that the edges of tile P4 are not parallel to the edges of adjacent tiles.

[0012] These alignment or positioning errors are problematic for the subsequent fabrication of electronic components in or on the tiles, which must follow a particularly careful schedule.

[0013] Furthermore, as shown in FIG. 2C, during a layer transfer operation or when multiple transfers from a pseudo donor substrate are performed in sequence, an edge effect phenomenon may be observed, which may damage the shape of the edges of the tiles P1-P4 and therefore affect the subsequent fabrication of components within or on the tiles, especially near the edges. Summary of the Invention

[0014] The object of the present invention is to design a process for manufacturing a structure comprising at least two tiles on a support substrate, which makes it possible to reduce tile positioning and alignment errors.

[0015] To this end, the invention relates to a process for manufacturing a structure comprising at least two tiles on a substrate, the process comprising: disposing at least two tiles on a support substrate, the tiles being arranged on the support substrate in an inaccurate distribution and / or geometric shape compared to a target distribution and / or geometric shape; forming a mask comprising a protective film partially covering the tiles in a pattern defining a target distribution and / or geometry and at least one opening extending around the protective film; Etching at least one tile through an opening in the mask to modify the arrangement of the tiles according to a target distribution and / or geometry. We propose a process that includes:

[0016] The term "etching" is used herein to mean a chemical and / or physical attack on the material of the tile that causes the elimination of zones of the tile that are not covered by the protective coating.

[0017] The mask is positioned using very precise techniques relative to the reference frame of the set of tiles, or relative to the reference frame of the supporting substrate on which the tiles extend, so that the tiles obtained after etching are precisely positioned and / or shaped.

[0018] "Reference frame" means herein a coordinate system associated with a substrate supporting the tiles, or a set of tiles, that makes it possible to define the position of each point on the surface of the substrate or set of tiles.

[0019] For example, the reference frame may include a reference point that may be located on an edge of the substrate, such as a notch conventionally 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. Such a reference frame is used to define the positions of components formed in or on the substrate and to localize the different steps of processes performed to form said components.

[0020] Alternatively, it is possible that the reference frame is not defined relative to the supporting substrate but relative to the set of tiles, for example said reference frame may be defined by one or more marks formed on at least one of the tiles and / or the supporting substrate.

[0021] In certain embodiments, the tiles are arranged in order on a supporting substrate.

[0022] In other embodiments, the tiles are disposed simultaneously on the supporting substrate.

[0023] In particular, the process comprises: forming a pseudo donor substrate by disposing each tile of at least one donor substrate on a first support substrate; Bonding the pseudo donor substrate to a second support substrate via a tile; transferring a portion of the tile to a second support substrate; may include.

[0024] In certain embodiments, the first support substrate and the second support substrate have the same diameter that is greater than the diameter of the donor substrate.

[0025] Particularly preferably, the pseudo donor substrate may be bonded to the second support substrate by molecular adhesion.

[0026] Transferring a portion of each tile may, in turn, include forming a weakened zone by implanting atomic species into each tile disposed on a quasi-donor substrate to define the portion to be transferred, bonding the quasi-donor substrate to a second support substrate via the tiles, and separating each tile along the weakened zone.

[0027] Each tile may typically have a thickness of between 20 μm and 1000 μm, preferably between 100 μm and 700 μm, and the transferred portion of each tile may have a thickness of between 30 nm and 1.5 μm.

[0028] The mask formation and etching may be performed after a portion of each tile has been transferred to the second support substrate. Alternatively or additionally, the mask formation and etching may be performed on the tiles of the pseudo donor substrate prior to bonding to the second support substrate.

[0029] In certain embodiments, each tile has a side having a length of 10 mm or less, preferably 5 mm or less, and more preferably 2 mm or less.

[0030] In other embodiments, each tile has a side with a length of 3 mm or more, preferably 5 mm or more, more preferably 8 mm or more.

[0031] A protective film preferably covers each tile in at least two patterns separated by an opening, and then etching the tile through the openings in the mask forms at least two portions of a tile from the tile in said patterns.

[0032] Particularly preferably, each tile has: semiconductor materials such as III-V materials, in particular indium nitride (InN), gallium nitride (GaN), aluminium nitride (AlN), indium arsenide (InAs), gallium arsenide (GaAs), aluminium arsenide (AlAs), indium phosphide (InP), gallium phosphide (GaP) or aluminium phosphide (AlP), or group IV or IV-IV materials, in particular germanium or silicon carbide (SiC); Lithium tantalate (LiTaO 3 ), lithium niobate (LiNbO 3 ), potassium sodium niobate (K x Na 1-x NbO 3 or KNN), barium titanate (BaTiO 3 ), quartz, lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), zinc oxide (ZnO), aluminum nitride (AlN) or aluminum scandium nitride (AlScN), and / or Electrically insulating materials such as diamond, strontium titanate, yttria-stabilized zirconia, or sapphire may include.

[0033] In a particular embodiment, the process includes forming at least one epitaxial layer on each tile, with mask formation and etching being performed after the epitaxy step.

[0034] Further features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0035] [Figure 1] 1A and 1B show top and cross-sectional views of a support substrate on which multiple tiles from a donor substrate are disposed. [Figure 2A] FIG. 2 is a top view of an example of alignment or geometric error of tiles on a support substrate of the type shown in FIG. 1. [Figure 2B]2 is a top view of another example of alignment or geometric error of tiles on a support substrate of the type shown in FIG. 1. [Figure 2C] 2 is a top view of yet another example of alignment or geometric error of tiles on a support substrate of the type shown in FIG. 1. [Diagram 3] FIG. 1 illustrates a particular embodiment of a pseudo donor substrate. [Figure 4A] 1A-1D show steps for removing tiles from a donor substrate. [Figure 4B] FIG. 2 illustrates the step of disposing the tile on a first support substrate to form a pseudo donor substrate. [Figure 4C] 4A-4D show steps of forming weakened zones in the tiles; [Figure 4D] FIG. 13 illustrates a step of bonding a pseudo donor substrate to a second support substrate via a tile. [Figure 4E] FIG. 13 illustrates the step of transferring a portion of the tile to a second support substrate after separating the tile along the weakened zone. [Diagram 5] 1A and 1B show top and cross-sectional views of a support substrate covered with tiles. [Figure 6] 6A and 6B are top and cross-sectional views of the structure in FIG. 5 after forming a mask on the tiles by photolithography, according to a first embodiment of the present invention. [Figure 7] 7A and 7B are top and cross-sectional views of the structure in FIG. 6 after etching of areas of the tile not covered by the mask. [Figure 8] 8A and 8B are top and cross-sectional views of the structure in FIG. 7 after removing the mask. [Figure 9A] FIG. 2B is a schematic diagram illustrating how the registration or geometry error shown in FIG. 2A is corrected by the present invention. [Figure 9B] FIG. 2C is a schematic diagram illustrating how the registration or geometry error shown in FIG. 2B is corrected by the present invention. [Figure 9C]FIG. 2D is a schematic diagram illustrating how the registration or geometry error shown in FIG. 2C is corrected by the present invention. [Figure 10] 6A and 6B are top and cross-sectional views of a support substrate covered with tiles having larger dimensions than the embodiment in FIG. 5. [Figure 11] 11A and 11B are top and cross-sectional views of the structure in FIG. 10 after forming a mask on the tiles by photolithography, according to a second embodiment of the present invention. [Figure 12] 12A and 12B are top and cross-sectional views of the structure in FIG. 11 after etching of areas of the tile not covered by the mask. [Figure 13] 13A and 13B are top and cross-sectional views of the structure in FIG. 12 after removing the mask. [Figure 14A] FIG. 3 shows a third embodiment of the invention in which tiles are arranged on a supporting substrate. [Figure 14B] FIG. 4 illustrates a third embodiment of the present invention in which an epitaxial layer is grown on each tile after the tiles are placed on a supporting substrate. [Figure 14C] FIG. 3 shows a third embodiment of the invention, in which the mask defined above is applied to the epitaxial layer. [Figure 14D] FIG. 4 illustrates a third embodiment of the present invention in which both the epitaxial layer and the tiles are etched to modify the geometry and / or distribution of the tiles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] For clarity, the drawings are not necessarily drawn to scale. Furthermore, the numbers of tiles shown diagrammatically in the drawings are given by way of example only.

[0037] The present invention proposes to correct distribution and / or geometric shape errors of tiles arranged on a support substrate in order to achieve a target distribution and / or geometry.

[0038] The distribution and / or geometry of the targets may be specified, for example, by a manufacturer of devices for microelectronics, optics or optoelectronics. In particular, the manufacture of such devices in or on each tile involves the use of local techniques that require precise location and shape for each tile.

[0039] For this purpose, after at least two tiles are placed on the support substrate, a mask is formed comprising a protective film partially covering the tiles. Said mask also comprises at least one opening around the film. Each opening forms an access point for an etchant, the composition of which is selected to chemically and / or physically attack the material of the tile. The protective film is made of a material that is resistant to the etchant and therefore protects the material of the tile from the etchant in the zones covered by the protective film. The application of the etchant therefore etches the material of the tile only in the zones not covered by the protective film, thereby making it possible to modify the geometry of the tiles. This modification of the geometry at the scale of each tile also makes it possible to modify the distribution or alignment of the tiles relative to one another.

[0040] Particularly preferably, the mask is formed by photolithography, and then the protective film is formed from a photosensitive resin that is resistant to the etchant, which is a chemical etching composition. Photolithography is generally more precise than the process for placing the tiles, and therefore makes it possible to ensure that the tile zones protected by the protective film conform to the target distribution and / or geometry.

[0041] Alternatively, the etchant is an ion beam (a technique known as "sputtering") and the mask comprises a metallic protective coating that protects the material of the tile from the ion beam in the zones covered by the protective coating.

[0042] The mask is removed after the tiles have been etched through all or part of their thickness.

[0043] It should be noted that it is possible to eliminate the use of a mask if a selective etching process is utilized that uses a controlled, focused etching ion beam only to sweep over the zones of the tile that are to be eliminated.

[0044] This process can be performed at different steps of the tiling process.

[0045] Thus, the process may be performed after tiles are placed on a first support substrate from one or more donor substrates.

[0046] The first support substrate can be a final support or a temporary support.

[0047] Additionally, the tiles may be placed sequentially, tile by tile, or simultaneously for sets of tiles.

[0048] Thus, for example, a first support substrate covered with tiles may be a pseudo donor substrate intended for subsequent transfer of the tiles to a second support substrate, which may be the final support or a new temporary support.

[0049] In this case, the tiles may be placed tile by tile onto a first support substrate, for example using a "pick and place" process, while the tiles may be simultaneously transferred from a pseudo donor substrate to a second support substrate.

[0050] The process for modifying the distribution and / or geometry of the tiles may be performed after the tiles are placed on the first support substrate and / or after the tiles are transferred to the second support substrate. Preferably, the process is performed after the tiles are transferred to the second support substrate in order to modify edge effects associated with the layer transfer step.

[0051] In certain embodiments, the number of tiles remains the same before and after the process is performed. This is especially true when the tiles have relatively small dimensions and the etching is performed primarily around the perimeter of each tile. For example, each tile initially has a side with a length of 10 mm or less, preferably 5 mm or less, more preferably 2 mm or less.

[0052] In another embodiment, the process allows for subdivision of the tile into several smaller tiles. The process thus has the advantage of forming tiles with very small dimensions without the need to place the tiles individually on a support substrate, and etching said tiles from a larger tile is quicker than placing each of the smaller tiles. For example, each tile initially has a side with a length of 3 mm or more, preferably 5 mm or more, preferably 8 mm or more.

[0053] Preferably, the tiles are made of a material that is not commercially available in the form of a donor substrate having large dimensions, so the donor substrate may have a diameter of less than 30 cm, for example about 10 or 15 cm.

[0054] This is particularly true for III-V semiconductor materials, including nitrides (e.g., for binary compounds, indium nitride (InN), gallium nitride (GaN), and aluminum nitride (AlN)), 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)).

[0055] This also applies to semiconductor Group IV or Group IV-IV compounds, such as germanium and silicon carbide.

[0056] The tiles can also be made of piezoelectric materials such as lithium tantalate (LiTaO 3 ) or lithium niobate (LiNbO 3), potassium sodium niobate (K x Na 1-x NbO 3 or KNN), barium titanate (BaTiO 3 ), quartz, lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), zinc oxide (ZnO), aluminum nitride (AlN), or aluminum scandium nitride (AlScN) (a non-limiting list).

[0057] The tiles can also be made of electrically insulating materials such as diamond, strontium titanate (SrTiO 3 ), yttria stabilized zirconia (YSZ) or sapphire.

[0058] Given the difference in size between the donor substrate and the support substrate, several donor substrates may be required to tile the entire surface of the support substrate, depending on the desired tiling density.

[0059] It should be noted that the tiles are not necessarily raised above the supporting substrate: for example, the tiles may be disposed within cavities formed in a major surface of the supporting substrate, with the top surfaces of the tiles being flush with or above or below the surface of the supporting substrate.

[0060] 3 is a schematic cross-sectional view of a pseudo donor substrate according to a particular embodiment, said substrate comprising tiles P1, P2, P3 and a first support substrate 2. Each tile is arranged in a respective cavity of substrate 2 formed in a main surface of said substrate 2 such that the free surface of the tile is substantially aligned (coplanar) with the surface of substrate 2.

[0061] As can be better seen in the insert showing a close-up of the tile P3 in its cavity, the free surface of each tile is located at a height h relative to the surface of the substrate 2. The height h may be 0 (the free surface of the tile and the main surface of the substrate are flush), positive (in which case the tile is slightly raised relative to the main surface of the substrate) or negative (in which case the tile is slightly recessed relative to the main surface of the substrate). In terms of absolute value, the height h is typically between 1 and 10% of the total thickness of the transferred part of the tile. Moreover, the height h may preferably be between a few tenths of a micrometer and a few tens of a micrometer.

[0062] Suitably, the raised, in other words positive height h, embodiment is the preferred embodiment in which the pseudo donor is configured to be bonded to a flat support substrate 3. Furthermore, a pseudo donor with recessed tiles (negative height h) can be bonded to a support substrate 3 with a surface including a topology configured to compensate for the topology of the pseudo donor substrate such that the recessed tiles are in contact with the surface of the support substrate 3.

[0063] 4A-4E show generally the formation of a pseudo donor substrate comprising tiles disposed on a first supporting substrate and the transfer of the tiles to a second supporting substrate.

[0064] With reference to FIG. 4A, the tiles P1 to P3 are cut from the donor substrate 2. The tiles may be cut using any technique known to the person skilled in the art. This may in particular be carried out by sawing and / or cutting or by laser cutting. This may also be combined with a step of partially plasma etching the cutting lines, for example a technique also known as "plasma dicing".

[0065] FIG. 4B shows placing a tile taken from the donor substrate in FIG. 4A onto a first support substrate 1 to form a pseudo donor substrate.

[0066] Placement may be performed using a "pick and place" technique, in which a robot picks up a tile previously cut from a donor substrate and places it in a predefined location on a first support substrate.

[0067] In a particular embodiment, each tile is attached to the first support substrate by molecular adhesion. For this purpose, a surface treatment of the tiles and / or of the first support substrate may be carried out beforehand in order to promote good molecular adhesion. These treatments may in particular be cleaning, applying silicon oxide (SiO 2 ), plasma activation prior to bonding, and annealing.

[0068] In other embodiments, the bonding of the tile to the first support substrate may include an intermediate bonding layer, for example a polymeric, eutectic or ceramic bonding layer.

[0069] The first support substrate 1 preferably has a diameter larger than that of the donor substrate 2, for example a diameter of about 300 mm.

[0070] 4C shows the formation of weakened zones in the tiles P1-P3 to define surface portions of the tiles intended to be transferred to a second support substrate. As indicated diagrammatically by the arrows, the weakened zones 11 are preferably formed by implanting atomic species such as hydrogen and / or helium into the tiles at a depth corresponding to the thickness of the layer to be transferred.

[0071] FIG. 4D shows bonding of the pseudo donor substrate in FIG. 4C to a second support substrate via a tile.

[0072] Particularly preferably, each tile is attached to the second support substrate 3 by molecular adhesion. For this purpose, a surface treatment of the tiles and / or the second support substrate may be carried out beforehand in order to promote good molecular adhesion. These treatments may in particular be cleaning, applying a layer of silicon oxide (SiO 2), plasma activation before bonding, polishing, and annealing, preferably at low temperature (meaning typically less than 300° C.).

[0073] The first support substrate 1 and the second support substrate 3 have the same diameter, for example about 300 mm.

[0074] Next, with reference to FIG. 4E, the tiles are separated along the weakened zones 11 in order to transfer the portions P'1, P'2, P'3 defined by said weakened zones to a second support substrate.

[0075] The tiles disposed on the first support substrate typically have a thickness of between 20 μm and 1000 μm, preferably between 100 μm and 700 μm. The transferred portion of each tile generally has a thickness of between 30 nm and 1.5 μm.

[0076] The process according to the invention can be performed on the quasi-donor substrate in FIG. 4B or FIG. 4C, and / or on the final structure in FIG. 4E.

[0077] The process steps are shown diagrammatically in Figures 5 to 8. These figures show tiles P1 to P3 and a support substrate S, but it goes without saying that depending on the structure to which the process is applied, tiles P1 to P3 may be replaced by tile portions P'1 to P'3 as shown in Figure 4E, and support substrate S may be the first support substrate 1 in Figure 4B or 4C or the second support substrate 3 in Figure 4E.

[0078] FIG. 5 shows a support substrate S on which a number of tiles P1-P3 are arranged. Considering the technique of cutting and / or placing the tiles, said tiles may have an inaccurate geometry compared to a target geometry and / or an inaccurate distribution compared to a target distribution. The target geometry may typically be characterized by the shape of the tile in a top view (top of FIG. 5) and / or the dimensions of the tile. The target distribution may be characterized by the alignment of the tiles with respect to each other, the distance between adjacent tiles, and / or the position of each tile in the coordinate system of the substrate S or the coordinate system of the set of tiles.

[0079] The different reference frames for the substrate and / or tiles are Before placement or transfer of tiles, on the outside of the tiles, onto a supporting substrate, on the tiles after they have been placed on or transferred to the support substrate, particularly during etching of selected tiles (e.g. the first tile to be placed, if placed using "pick and place" techniques, or a transferred tile, selected depending on its position or the quality of its transfer, if tiles are transferred simultaneously to the support substrate); It may be defined with respect to a positioning mark provided (eg in the form of a cross).

[0080] An example of a coordinate system (O,x,y) of a substrate S is shown diagrammatically in FIG. 5. In this example, point O is the center of the substrate S. The axis (Ox) passes through a notch N already present in the edge of the substrate S. The axis (Oy) is perpendicular to the axis (Ox). Of course, other coordinate systems may be used without departing from the scope of the invention.

[0081] FIG. 6 illustrates the formation, for example by photolithography, of a mask comprising protective films M1-M3 partially covering each tile P1-P3 and an opening extending through a portion of the protective film.

[0082] The overcoat defines a pattern that corresponds to the target geometry and / or distribution of the tiles.

[0083] The film can be made of any suitable resin. In particular in the field of microelectronics, such photosensitive resins, sold for example by the company Shipley or the company AZ Electronic Materials, are supplied in a viscous state and are distributed on the substrate with the help of a spinner (known as a "spin-coating" operation) and then annealed. A UV irradiation step makes it possible for these resins to retain the exposed zones after they have been exposed or, on the contrary, to eliminate them. According to a variant known as "dry film photoresist", these resins can also be applied by lamination of thick films, typically with a thickness between 15 and 50 μm, supplied in the form of rolls.

[0084] Referring to FIG. 7, an etchant is applied to the structure of FIG. 6. The composition of the etchant is selected depending on the material of the tile. For example, when the tile is made of InP, hydrochloric acid (HCl) and phosphoric acid (H 3 PO 4 Wet etching in a bath of 10 ... 4 / H 2 ) Mixture-based) plasma etching may also be used.

[0085] Preferably, the etching solution does not attack, or only slightly attacks, the material of the substrate S.

[0086] Alternatively, etching, for example by ion beam sputtering of argon, can also be used, in which case the protective coating is preferably metallic.

[0087] At the end of the etching, the peripheral parts of the tiles that are not covered by the protective film have been removed over all or part of the thickness of the tiles. In certain embodiments, especially when the process is carried out on a pseudo donor substrate before the tiles are transferred to another substrate, it may be sufficient to etch the tiles over only a part of their thickness. This etched part may typically have a thickness equal to or greater than the transferred thickness, or equal to or greater than a multiple of the transferred thickness when the pseudo donor substrate needs to be used several times to transfer the tiles. Thus, purely as a guide, the thickness of the etched part may be several tens of micrometers. In other situations, especially when the process is carried out after the tiles have been transferred, for example, to a final substrate, it may be preferable to etch the tiles over their entire thickness.

[0088] Thus, on the support substrate S there are tiles whose geometry and / or distribution matches the target geometry and / or distribution.

[0089] Optionally, the etching step may be exploited to form on the support substrate and / or on one or more tiles one or more alignment marks intended to make it easier to locate the different tiles for a subsequent technological step. In particular, this type of alignment mark is preferably useful for performing a specific subsequent technological step, in particular a lithography step. Furthermore, it is common that not all steps are performed in one and the same fabrication unit, but rather that they involve packaging and transport to another location of a structure that has undergone a specific manufacturing step, in order to perform the following manufacturing step with reference to said alignment marks.

[0090] With reference to Fig. 8, the protective film is removed to release the surface of the tile. The structure is thus ready for subsequent manufacturing steps, such as deposition or epitaxy of one or more additional layers on the tile, formation of electronic components in or on the tile, etc. When the support substrate S is not the final support, the tile can be transferred to a new support substrate before or after the above-mentioned manufacturing steps are performed.

[0091] 9A-9C show examples of modifying the geometry and / or distribution of tiles.

[0092] In the case of Figure 9A, which corresponds to the error shown in Figure 2A, the alignment error of tile P4 relative to tiles P2 and P3 is corrected by using a mask in which portions M2 and M4 are aligned horizontally and portions M3 and M4 are aligned vertically, so that following etching, the tiles in portions M2, M3, and M4 of the protective film are perfectly aligned.

[0093] In the case of Figure 9B, which corresponds to the error shown in Figure 2B, by using a mask in which portions M2 and M4 are aligned horizontally and portions M3 and M4 are aligned vertically, the orientation error of tile P4 relative to tiles P2 and P3 is corrected, and the portion of the protective film M4 is inscribed in the geometry of tile P4. As a result, following etching, the tiles in the protective film portions M2, M3 and M4 are perfectly parallel and aligned.

[0094] In the case of Figure 9C, which corresponds to the error shown in Figure 2C, the edge irregularities of tiles P1-P4 caused by layer transfer have been corrected by the use of a mask whose portions M1-M4 have a geometry that matches the desired geometry, such that each portion M1-M4 of the protective film is inscribed within the geometry of its respective tile P1-P4.

[0095] As mentioned above, the process according to the invention can also be used to subdivide a tile into several smaller tiles, in which case, even if the tiles are perfectly aligned, the geometric shape and / or distribution errors may be considered inaccurate simply because the number of tiles placed on the support substrate does not correspond to the number of tiles expected.

[0096] 10-13 show such an embodiment of the process.

[0097] As shown in Figure 10, four tiles P1-P4 are arranged on a support substrate S. The tiles may be arranged directly from a donor substrate, for example by "pick and place" techniques, or from a pseudo donor substrate according to the process shown in Figures 4A-4E.

[0098] The tiles have relatively large dimensions that are larger than those required to fabricate the intended component. More specifically, each tile has a dimension that is greater than a multiple of the tile's targeted dimension in the manufacturing process. For example, each tile may have a dimension that is two or four times the targeted dimension.

[0099] Referring to FIG. 11, a mask is formed over the tiles, for example by photolithography, to define the desired pattern for the final tile.

[0100] The mask comprises several portions of protective film on each tile, so that tile P1 is covered with four portions of protective film M11, M12, M13, M14, which are separated by openings in the form of a cross.

[0101] Referring to Figure 12, an etchant is applied to the structure in Figure 11. As a result, not only the perimeter of the tile but also the central portion not covered by the protective film is etched.

[0102] Referring to FIG. 13, the protective film is removed to release the surface of the tile.

[0103] Thus, at the end of etching, each tile (eg, tile P1) has been subdivided into four tiles (P11, P12, P13, P14 respectively).

[0104] In the illustrated example, the distance between tile P1 and the adjacent tiles is greater than the distance between tiles P11-P14 formed from tile P1. However, it is of course possible to arrange the initial and final tiles so as to form a matrix of tiles having a perfectly regular geometric shape, in which the distances between the resulting tiles are identical. Conversely, by masking and local etching it is possible to form a matrix of tiles having a complex geometric shape.

[0105] Compared to a process in which each tile P11-P14 is individually placed on a supporting substrate S, for example using "pick-and-place" techniques, the formation of tiles P11-P14 according to the present invention is quicker as it only involves one step of placing tile P1.

[0106] The process according to the invention can be carried out directly on tiles arranged on a first support substrate or on tiles transferred to a second support substrate, but particularly preferably, when one or more additional layers are formed on the tiles, the process according to the invention can be carried out after the formation of said one or more additional layers.

[0107] 14A-14D show an embodiment of a process in which epitaxial layers E1, E2, E3 (see FIG. 14B) are formed on each tile P1, P2, P3 (see FIG. 14) arranged on a support substrate S. For example, the tiles are made of a monocrystalline material having a lattice parameter and crystalline quality suitable for epitaxial growth of the layers E1-E3. The layers E1-E3 may be made of the same material as the tiles, the epitaxial growth allowing the tiles to be thickened. Alternatively, the epitaxial layers E1-E3 may be made of a material different from that of the tiles, the epitaxial growth allowing a composite stack to be formed.

[0108] As shown in FIG. 14C, a protective film M1, M2, M3 forming a mask is deposited on the surface of each epitaxial layer E1, E2, E3.

[0109] 14D, an etchant suitable for attacking the material of the tiles and the material of the epitaxial layer is applied. At the end of the etching, only the material of the tiles and the epitaxial layer remains, protected by the protective film.

[0110] The protective film can then be removed to free the surface of the epitaxial layer to allow continuation of processes to fabricate electronic components in or on the tiles and epitaxial layer.

[0111] The present invention thus allows adjustment of tile geometry and alignment to be deferred until the most appropriate stage in the manufacturing process.

[0112] (Examples) The present invention presents different cases of particularly suitable application, especially in the field of microelectronics.

[0113] According to a first embodiment, the process may make it possible to modify the geometry and distribution of a number of tiles having relatively large dimensions (i.e. having sides several millimeters long), spaced apart by several millimeters and arranged on a support substrate having a diameter of 300 mm, said support substrate being a silicon substrate or a substrate of silicon-on-insulator (SOI) type.

[0114] In photonic applications, the active layer of the SOI may comprise a photonic circuit with passive or active devices, such as one or more waveguides, one or more multiplexers, one or more microresonators, etc. The tiles transferred onto this layer may be made of InP, a material more suitable than silicon for epitaxial growth of stacks of III-IV materials to form lasers.

[0115] Given that the size of the InP tiles is relatively large, optionally several circuits can be created with each tile.

[0116] According to an alternative embodiment, the above-mentioned tiles are subdivided by the process according to the invention into tiles of smaller dimensions, each initial tile defining a cell comprising a number of chips each formed by a tile of smaller dimensions. It is thus possible to form two arrangement levels of tiles on the support substrate, a first level on the scale of the cells arranged on the support substrate in a first pattern, and a second level on the scale of the chips arranged in each cell in a second pattern.

[0117] In radio frequency (RF) applications, the active layer of the SOI may comprise components operating at relatively low frequencies, while the tiles, preferably made of InP or GaN, may comprise components operating at higher frequencies. In such applications, the size of the tiles may measure up to 1 cm on a side after their alignment and / or geometric modification. The tiles are preferably densely arranged on a support substrate, with the distance between the tiles being typically less than 300 μm, for example, after alignment and / or geometric modification.

[0118] For micro-LED applications, the size of the GaN tiles is preferably less than 50 μm after their alignment and / or geometric modification.

Claims

1. 1. A process for manufacturing a structure comprising at least two tiles on a substrate, comprising: - arranging at least two tiles ((P1, P2), (P'1, P'2)) on a support substrate (1, 3, S), said tiles being arranged on said support substrate (1, 3, S) with an inaccurate distribution and / or geometric shape compared to a target distribution and / or geometric shape; forming a mask comprising a protective film (M1, M2) partially covering said tiles ((P1, P2), (P'1, P'2)) in a pattern defining the distribution and / or geometric shape of said targets and at least one opening extending around said protective film (M1, M2); Etching at least one tile ((P1, P2), (P'1, P'2)) through the opening in the mask so as to modify the arrangement of the tiles according to the target distribution and / or geometry. The process includes:

2. The process of claim 1 , wherein the pattern is defined in a coordinate system of the set of tiles.

3. The process of claim 1 , wherein the pattern is defined in a coordinate system of the supporting substrate.

4. The process according to any one of claims 1 to 3, wherein the tiles (P1, P2) are arranged in sequence on the support substrate.

5. The process according to any one of claims 1 to 3, wherein the tiles (P'1, P'2) are placed simultaneously on the supporting substrate.

6. forming a pseudo donor substrate by disposing each tile of at least one donor substrate (2) on a first support substrate (1); Bonding the pseudo donor substrate to a second support substrate (3) via the tiles (P1, P2); transferring a portion of said tile (P'1, P'2) to said second support substrate (2); The process of claim 5, comprising:

7. The process of claim 6 , wherein the first support substrate and the second support substrate have the same diameter that is greater than a diameter of the donor substrate.

8. The process according to claim 6 or 7, wherein the pseudo donor substrate is bonded to the second support substrate (3) by molecular adhesion.

9. 9. The process according to claim 6, wherein the transfer of a portion of each tile in turn comprises the steps of forming a weakened zone (11) by implanting an atomic species in each tile arranged on the pseudo donor substrate to define the portion to be transferred, bonding the pseudo donor substrate to the second support substrate via the tiles, and separating each tile along the weakened zone.

10. 10. The process of claim 9, wherein each tile 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.

11. The process of any one of claims 6 to 10, wherein the forming of the mask and the etching are performed after a portion of each tile has been transferred to the second support substrate.

12. The process of any one of claims 6 to 11, wherein the forming of the mask and the etching are performed on the tiles of the pseudo donor substrate before bonding to the second support substrate.

13. The process of any one of claims 6 to 12, wherein each tile is positioned within a cavity in the first support substrate to form the pseudo donor substrate.

14. A process according to any one of the preceding claims, wherein each tile has a side with a length of 10mm or less, preferably 5mm or less, more preferably 2mm or less.

15. A process according to any one of the preceding claims, wherein each tile has a side with a length of 3mm or more, preferably 5mm or more, more preferably 8mm or more.

16. 15. The process of claim 14, wherein the protective film covers each tile in at least two patterns separated by an opening, and the etching of the tile through the openings in the mask forms at least two portions of a tile from the tile in the pattern.

17. Each tile is Semiconductor materials such as III-V materials, in particular indium nitride (InN), gallium nitride (GaN), aluminium nitride (AlN), indium arsenide (InAs), gallium arsenide (GaAs), aluminium arsenide (AlAs), indium phosphide (InP), gallium phosphide (GaP) or aluminium phosphide (AlP), or IV or IV-IV materials, in particular germanium or silicon carbide (SiC), Lithium tantalate (LiTaO ３ ), lithium niobate (LiNbO ３ ), potassium sodium niobate (K ｘ Na １－ｘ NbO ３ or KNN), barium titanate (BaTiO ３ ), quartz, lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), zinc oxide (ZnO), aluminum nitride (AlN) or aluminum scandium nitride (AlScN), and / or Electrically insulating materials such as diamond, strontium titanate, yttria-stabilized zirconia, or sapphire The process according to any one of claims 1 to 16, comprising:

18. The process according to any one of claims 1 to 17, comprising forming at least one epitaxial layer (E1, E2, E3) on each tile (P1, P2, P3), wherein said forming of the mask and said etching are performed after the epitaxy step.

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