Semiconductor substrate for laser debonding, and manufacturing method

Abstract

The invention relates to a substrate (SUB) that is able to release a thin layer under the effect of light irradiation, the substrate comprising: a silicon carrier substrate (WafCar) having a top surface (TopCar) and a bottom surface (BotCar) opposite to the top surface; an insulating layer (Ox1Car, SiNCar) covering each of the top surface and the bottom surface; a separation layer (TiNCar) formed on the top surface (TopCar) of the carrier substrate (WafCar); and a layer (TL) to be released on the top surface of the carrier substrate (WafCar), with the separation layer (TiNCar) between the layer (TL) to be released and the carrier substrate.

Description

SEMICONDUCTIVE SUBSTRATE FOR LASER PEEL-ON AND MANUFACTURING PROCESS FIELD OF INVENTION

[0001] The present invention relates to the field of the semiconductor industry and proposes a semiconductor substrate designed to allow laser peeling of a thin, possibly single-crystal, layer. CONTEXT OF THE INVENTION

[0002] The semiconductor industry is increasingly using thin film transfer techniques, which consist of forming a thin film on a first substrate called a "donor substrate", then transferring the thin film formed onto a second substrate, called a "carrier substrate" or "manipulation substrate".

[0003] The donor substrate can be chosen for its compatibility with the conditions for thin film formation, or the thin film can be formed within the mass of the material forming this donor substrate.

[0004] The carrier substrate is adapted to the processing of this thin film, for example by being compatible with subsequent manufacturing steps, or even by carrying a structure onto which the thin film will be integrated. Ultimately, a fabricated thin film comprising the thin film, or only a portion of it remaining after the manufacturing steps, must be transferred onto a third substrate, called the "receiving substrate".

[0005] Among the thin film transfer techniques used in the semiconductor industry, laser lift-off (LLO) has established itself as an efficient method for separating a film or stack of films, or one or more thin films, from a carrier substrate using a layer, called a separation layer, whose separation or degradation is triggered by thermal energy from light irradiation, such as laser irradiation.

[0006] Typically, the separation layer is irradiated by a laser through the carrier substrate. The separation layer must absorb sufficient light at the laser wavelength to promote separation or degradation (for example, by locally melting the separation layer or causing its dissociation into elementary components), while the carrier substrate must be substantially transparent at that wavelength. A balance between laser power, laser wavelength, and material selection (for both the separation layer and the carrier substrate) must be found to enable separation while protecting the layer(s) to be transferred from the influence of energy dissipation due to light interaction processes: heat transfer due to absorption in the separation layer or direct absorption of some of the laser irradiation by the layer(s) to be transferred.

[0007] US patents 2014 / 327049, US 2023 / 207661, CN 113 097 124 each describe a method for manufacturing semiconductor devices involving separation facilitated by laser irradiation.

[0008] However, there are other needs in terms of quality and reliability of the conventional process described above, as well as with regard to its cost.

[0009] A first object of the invention is a substrate adapted to release a thin layer under the effect of light irradiation, the substrate comprising: a carrier substrate made of silicon and having a top surface and a bottom surface opposite the top surface; an insulating layer covering each of the top surface and the bottom surface; a separation layer formed on a top surface of the carrier substrate; and a layer to be released on the top surface of the carrier substrate with the separation layer interposed between the layer to be released and the top surface of the carrier substrate.

[0010] The fact that the insulating layer covers both the upper and lower surfaces of the substrate advantageously prevents, or at least limits, substrate warping, particularly during operations requiring heating. Consequently, the operations to be applied to the layer to be detached, which include bonding this layer to a receiving substrate, are facilitated. It is indeed preferable to process and handle devices that are flat rather than those that exhibit warping.

[0011] According to other non-limiting features of the invention, considered individually or in any technically feasible combination:

[0012] - the insulating layer can also cover an edge of the supporting substrate connecting the upper surface and the lower surface;

[0013] - the insulating layer may include a dielectric layer and an internal oxide layer interposed between the dielectric layer and the carrier substrate;

[0014] - the dielectric layer can be a layer made of silicon nitride;

[0015] - the inner oxide layer (Ox1 Car ) of silicon oxide;

[0016] - the separation layer can be made of titanium nitride;

[0017] - a layer of bonding oxide can be interposed between the separating layer and the layer to be separated;

[0018] - the bonding oxide layer may include a support oxide layer in direct contact with the separation layer and a donor oxide layer in direct contact with the layer to be released, in which at least one of the support oxide layer and the layer to be released may protrude from the donor oxide layer when viewed in a cross-sectional view of the substrate;

[0019] - the layer to be released can be made of a single-crystal material;

[0020] - the carrier substrate and the separation layer can be respectively transparent and absorbent to light of a given wavelength, so that the layer to be released can be separated from the carrier substrate when light of a given wavelength is irradiated through the carrier substrate.

[0021] Another advantage is that the dielectric layer, possibly a nitride or silicon nitride layer, prevents contamination of the internal oxide layer and the carrier substrate by the material forming the separation layer, which can be formed from TiN, and whose function is to allow a laser peeling process to release the layer to be released.

[0022] A second object of the invention is a method for manufacturing a substrate capable of releasing a thin film under the effect of light irradiation, the method comprising the following steps: formation of an insulating layer covering each of a top surface and a bottom surface of a carrier substrate made of silicon, the bottom surface being opposite the top surface; formation of a separation layer on the top surface of the carrier substrate; and formation of a layer to be released on the top surface of the carrier substrate, the separation layer being interposed between the layer to be released and the top surface of the carrier substrate.

[0023] This method makes it possible to obtain the substrate according to the first object of the invention, with its advantages.

[0024] According to other non-limiting features of the invention, considered individually or in any technically feasible combination:

[0025] - the step of forming the insulating layer covering each of the upper and lower surfaces of the carrier substrate can use a substantially conformal deposition method, preferably a low-pressure chemical vapor deposition;

[0026] - the insulating layer formation step and the separation layer formation step can respectively use a first deposition method and a second deposition method, the second deposition method being more directive than the first deposition method;

[0027] - the step of forming the layer to be released may include the following steps: bonding a donor substrate to the upper surface of the carrier substrate with the separation layer interposed between the donor substrate and the upper surface of the carrier substrate; and removal of part of the donor substrate, another part of the donor substrate remaining on the carrier substrate;

[0028] - the step of bonding a donor substrate to the upper surface of the carrier substrate can be an oxide-oxide type bonding step.

[0029] Other features and advantages of the invention will become apparent from the detailed description of the invention that follows, with reference to the accompanying figures, in which:

[0030] Laillustre un process de fabrication de un substrat selon la invention;

[0031] Laillustre the typical geometries of a silicon wafer seen in plan view;

[0032] Laillustre les geometries typiques d'une wafer de silicon en section cross ;

[0033] Laillustre a substrate obtained by the manufacturing process of the;

[0034] Laillustrates a manufacturing process using the substrate of the.

[0035] DETAILED DESCRIPTION OF A SPECIFIC EMBODIMENT OF THE INVENTION

[0036] Implementation of the invention

[0037] A first embodiment of the invention is explained with the aid of Figures 1 to 3 and 4, which illustrate the manufacture of a SUB semiconductor substrate designed to allow laser peeling of a layer to be released, generally a layer of active material such as single-crystal silicon.

[0038] Laillustre illustrates the steps of a PR1 method for fabricating a SUB semiconductor substrate designed to allow laser peeling of a TL layer to be transferred onto a Waf receiving substrate ( Rec).

[0039] A Waf load-bearing substrate Car is prepared in steps 10 to 16, a Waf donor substrate Donest préparé aux étapes 20 à 24, une couche du substrat donneur est transférée sur le substrat porteur et finalisée aux étapes 30 à 32.

[0040] Preparation of the Waf carrier substrate Car

[0041] In step 10, a Waf carrier substrate Caris provided. The carrier substrate can be a substrate conventionally used in the semiconductor industry, such as a semiconductor wafer, such as a silicon wafer, preferably a raw silicon wafer, i.e., a bare silicon wafer, on which no layer has been intentionally deposited. The carrier substrate has a top surface Caret une surface inférieure BotCarqui forment deux surfaces planes parallèles, comme illustré à la(A1).

[0042] In step 12 following step 10, an internal oxide layer Ox1 Car is formed at least on the upper and lower surfaces of the substrate. The Ox1 oxide layer Car can be formed by thermal oxidation of the carrier substrate, to form a silicon oxide layer with a thickness between 10 nm and 600 nm, preferably between 50 nm and 200 nm. Through this process, the Ox1 oxide layer Carcovers virtually the entire carrier substrate, including the upper and lower surfaces as well as the edge of the carrier substrate connecting these two surfaces, as illustrated in (A2). An internal oxide layer formed by thermal oxidation of the carrier substrate is advantageous for the simplicity and reliability of the manufacturing process, and for the quality of the layer obtained, but other dielectric materials could be used.

[0043] In step 14 following step 12, a SiN dielectric layer Car can be formed, at least on the upper and lower surfaces of the substrate. The dielectric layer can be formed from a silicon alloy with a density greater than that of silicon dioxide. A relatively high density, here higher than that of silicon dioxide, with a typical density between 2.20 and 2.27 g / cm³, is required. 3The dielectric layer allows the dielectric layer to block the diffusion of the material forming the separation layer and prevents contamination of the internal oxide layer and the substrate by this material. The SiN dielectric layer Carpeut être formée par le dépôt de 10 nm à 200 nm de nitrure ou d'oxynitrure de silicium par dépôt chimique en phase vapeur à basse pression ou LP-CVD. Le dépôt chimique en phase vapeur à basse pression peut être utilisé pour réaliser un revêtement conforme d'un substrat. Dans le cas présent, la formation de la couche diélectrique par une technique de dépôt conforme telle que le LP-CVD permet de former la couche diélectrique de manière à couvrir la quasi-totalité du substrat porteur, ce qui inclut les surfaces supérieure et inférieure ainsi que le bord du substrat porteur reliant ces deux surfaces, comme illustré par la(A3). Selon un autre mode de réalisation, la couche diélectrique (par exemple le nitrure ou l'oxynitrure de silicium) peut être déposée par PE-CVD, et dans ce cas, ladite couche est déposée sur la surface supérieure et la surface inférieure du substrat porteur.

[0044] The internal oxide layer Ox1 Car and the SiN dielectric layer Car collectively form an insulating layer covering each of the top surface Caret de la surface inférieure BotCardu substrat porteur WafCar.

[0045] In step 16 following step 14, a TiN separation layer Car is formed on the upper surface Top Car of the carrier substrate. If oxide-to-oxide bonding is planned in a later step, a bonding oxide layer Ox2 Carpeut éventuellement être formée par de l'oxyde de silicium sur la couche de séparation TiNCar, comme illustré à la(A4).

[0046] The TiN separation layer Carcan be deposited with a thickness ranging from 10 nm to 400 nm using plasma-enhanced chemical vapor deposition (PE-CVD) or physical vapor deposition (PVD) techniques. The bonding oxide layer, Ox2 Car , can be deposited with a thickness between 10 nm and 400 nm by plasma-enhanced chemical vapor deposition (PECVD) of silicon dioxide.

[0047] The methods used to form the TiN separation layer Car and the Ox2 bonding oxide layer Car are preferably more directive than the methods used to form the internal oxide layer Ox1 Car and the SiN dielectric layer Car , which leads to the geometry illustrated by (A4), with the internal oxide layer Ox1 Car and the SiN dielectric layer Car covering the upper and lower surfaces of the Waf carrier substrate Car, tandis que seule la surface supérieure TopCarest couverte par la couche de séparation TiNCaret la couche d'oxyde de collage Ox2Car. On peut également constater que, dans ce mode de réalisation spécifique, une partie latérale de la couche diélectrique SiNCarest en contact direct avec l'atmosphère, non couverte par la couche d'oxyde de collage Ox2Car, tandis que les bords du substrat porteur WafCarsont couverts par la couche d'oxyde interne Ox1Caret la couche diélectrique SiNCar.

[0048] Preparation of the Waf donor platelet Don

[0049] In step 20, a Waf donor substrate Don is provided. The donor substrate can be a substrate conventionally used in the semiconductor industry, such as a semiconductor wafer, such as a silicon wafer, preferably a raw silicon wafer, i.e., a bare silicon wafer without any layer having been intentionally deposited on it. The donor substrate has a top surface Donet une surface inférieure BotDonqui forment deux surfaces planes parallèles, comme illustré à la(B1).

[0050] In step 22 following step 20, a layer of donor oxide Ox Don is formed at least on the upper and lower surfaces of the donor substrate. The Ox oxide layer Donpeut être formée par oxydation thermique du substrat donneur, pour former une couche d'oxyde de silicium d'une épaisseur comprise entre 10 nm et 500 nm lorsque le substrat donneur est formé de silicium. Grâce à ce processus, la couche d'oxyde OxDoncouvre la quasi-totalité du substrat donneur, qui comprend les surfaces supérieure et inférieure ainsi que le bord du substrat donneur reliant ces deux surfaces, comme l'illustre la(B2).

[0051] It is also possible to use other types of donor substrates, in combination with a conformal deposition method such as LP-CVD to form an Ox oxide layer Doncovering the donor substrate.

[0052] In step 24, to define a thin layer of the material forming the donor wafer and to prepare its separation from the rest of the donor wafer, an ion implantation process (ImP) is implemented: a light ion species, hydrogen (H₂), is implanted. + or helium He + or both, is introduced into the Waf donor substrate Don through the top surface Donpour former un plan de fragilisation ou de fragilisation FrglDonà l'intérieur du substrat donneur. Le plan de fragilisation est sensiblement parallèle à la surface supérieure TopDon, comme l'illustre la(B3). Le volume du substrat donneur compris entre la surface supérieure TopDonet le plan de fragilisation Frgl définit une couche mince TL qui sera ultérieurement transférée sur le substrat porteur, puis sur un substrat récepteur. La couche mince TL sera détachée du reste du substrat donneur WafDonpar la technologie Smart CutTM.

[0053] The introduction of ions can correspond to hydrogen implantation, that is, ion bombardment of the upper surface. Don of the donor substrate with hydrogen ions. Generally, the type, dose, and energy of the implanted species are chosen based on the desired thickness of the layer to be transferred and the physicochemical properties of the donor substrate. These parameters can be adjusted to define the thickness of the thin film (TL) between 5 nm and 2 µm.

[0054] The carrier wafer and the donor wafer can independently exhibit the geometric characteristics of the Waf wafers illustrated in Figures 2 and 3. Lamontre shows that the Waf wafer generally has a substantially circular edge Edg with at least one flat fla ((A)) or notch ((B)) which can be used to orient the wafer according to its crystallographic characteristics, if applicable.

[0055] Laillustrates the Waf slice in a cross-sectional view, showing different edge profiles, with a rounded edge at (A) and a beveled edge at (B). The edge profiles connect to a top surface. ( Waf ) of the Waf slice to a lower Bot surface ( Waf ) of the Waf bracket.

[0056] Assembly and finalization of the SUB substrate

[0057] Once the donor wafer and the carrier wafer are prepared, they are bonded together in a gluing step 30: the layers covering the upper surfaces of the Waf donor substrate Don and the Waf carrier substrate Carsont mises en contact intime et subissent une adhésion moléculaire et / ou un collage électrostatique entre elles, comme mentionné par exemple dans la demande de brevet français publiée sous le numéro 2 914 492. Dans le présent mode de réalisation, un collage oxyde-oxyde est réalisée entre la couche de collage Ox2Caret la couche d'oxyde de donneur OxDon. Les surfaces mises en contact intime peuvent être préparées par nettoyage, brossage, séchage, polissage ou activation par plasma, comme cela est connu dans le domaine. L'ensemble obtenu comprend les couches suivantes, empilées dans cet ordre : substrat porteur WafCar, couche d'oxyde interne Ox1Car, couche diélectrique SiNCar, couche de séparation TiNCar, couche de collage Ox2Car, couche d'oxyde de donneur OxDonet substrat donneur WafDon, comme illustré par la(C1).

[0058] As is known, during a molecular adhesion process, the exposed surfaces of the insulating layer and the donor substrate, which are perfectly clean, flat, and smooth, are brought into intimate contact to promote electrostatic bonding or the development of molecular bonds, such as van der Waals or covalent bonds. The two bodies are then joined without the use of an adhesive. The bonding process may involve the application of a low-temperature heat treatment (e.g., between 50 and 300°C, typically 100°C) to heal crystalline defects in the donor substrate and sufficiently increase the bonding energy to allow for a possible subsequent thinning step or other processing.

[0059] In step 32 following step 30, a cleavage process is carried out to cleave the Waf donor substrate Don at the level of the weakening plane Frgl so as to leave the thin layer TL fixed to the carrier substrate WafCar. La structure obtenue après le clivage est le substrat semi-conducteur SUB illustré par la(C2).

[0060] More specifically, after the 30th bonding step, the TL thin layer is detached from the rest of the Waf donor substrate Don by fracture at the level of the weakening plane Frgl and is therefore transferred to the load-bearing substrate Waf Car. Cette étape de détachement peut impliquer l'application d'un traitement thermique à une température comprise entre 350°C et 1000° pour détacher la couche mince TL du substrat donneur et achever son transfert sur le substrat porteur WafCar. En alternative ou en complément du traitement thermique, cette étape peut consister à appliquer une lame ou un jet de fluide gazeux ou liquide, ou toute autre force mécanique sur le plan de fragilisation Frgl.

[0061] After step 32, which produces the SUB structure illustrated by (C2), a stabilizing heat treatment can optionally be applied to the SUB substrate in a post-cleavage step. This stabilizing heat treatment heals crystalline defects in the TL thin film and helps consolidate the bond between the TL thin film and the carrier substrate, for example, by heating the Sub substrate to a temperature between 300°C and 600°C for a period of 30 minutes to 10 hours. This heat treatment is preferably carried out by exposing the free face of the TL thin film to a neutral gaseous atmosphere.

[0062] After step 32, a smoothing step of the free surface of the TL thin film, for example by CMP (Chemical Mechanical Polishing), wet etching and / or heat treatment.

[0063] Figures 1(C2) and 4 illustrate the resulting SUB substrate. At this stage, the SUB semiconductor substrate can be ready for any processing intended by the user of the SUB substrate.

[0064] The semiconductor substrate can also be sent to the user without the smoothing step having been performed, allowing the user to carry out a smoothing step of their choice. This is because the SUB semiconductor substrate is intended for use by various parties, and the manufacturing unit where it was produced will generally be different from the manufacturing unit where the active material layer will be processed to form a functional semiconductor device or part of such a device.

[0065] Furthermore, as an alternative to the formation of a weakening plane and the fracture of the donor substrate at this plane, the donor substrate can be thinned after assembly with the carrier substrate, for example by etching, grinding, and / or chemical mechanical polishing (CMP). This thinning can be used to remove the donor substrate entirely or only partially, for example, to achieve the situation illustrated by (C2).

[0066] Depending on the edge profiles of the WafCar carrier wafer, the WafDon donor wafer, and their alignment at step 30, the TiN layers Car and Ox2 Car may exhibit a protrusion that extends beyond the donor oxide layer Ox Don and the TL thin layer when viewed in cross-section of the SUB substrate, as illustrated. It can also be said that the lateral edges of the donor oxide layer Ox Donet de la couche mince TL sont en retrait par rapport aux bords latéraux des couches TiNCaret Ox2Car.

[0067] Example of using the SUB substrate

[0068] Laillustrates the steps of a PR2 method for laser delamination of a TL layer to be transferred from the SUB substrate to a Waf receiving substrate Rec .

[0069] At step 100, the Waf receptor substrate Rec is provided. The Waf substrate Recpeut être n'importe quel type de substrat plat ayant une surface lisse, tel que le substrat couramment utilisé dans l'industrie des semi-conducteurs : Si, SiC, saphir, verre, AlN ou toute combinaison de ces matériaux. Le substrat récepteur WafReca une surface supérieure TopRec, comme l'illustre la(B1). En tout état de cause, le substrat récepteur doit être compatible avec un procédé de collage pour le transfert de couches minces TL et avec l'utilisation prévue d'un dispositif à fabriquer.

[0070] In step 200, the SUB substrate obtained by the PR1 method is provided, as illustrated by (B1).

[0071] In step 300, the thin TL layer is bonded to the top surface. Rec of the Waf receptor substrate Rec, comme illustré à la(C1). Le même processus que celui de l'étape 30 de collage direct peut être exécuté. Bien qu'elle ne soit pas représentée sur la, une couche (une monocouche ou une multicouche formée de plusieurs couches) favorisant le collage entre la couche mince TL et le substrat récepteur WafRecpeut éventuellement être formée. Par exemple, dans le cas d'un collage oxyde-oxyde, une couche d'oxyde peut être déposée sur la couche mince TL et une couche d'oxyde peut être formée sur la surface supérieure TopRecdu substrat récepteur WafRec.

[0072] After the fabrication of the SUB substrate and before step 300, the TL thin film may have undergone various fabrication steps to form a structure to be transferred onto the Waf receiving substrate Rec .

[0073] In step 302 following step 300, light is irradiated through the TiN separation layer Carthrough the Waf carrier substrate Car , as illustrated by Irr in the. By absorbing the energy of the light irradiation Irr, the TiN separation layer Car is heated locally and degrades, releasing the thin TL layer. By mechanical traction Trac, the Waf carrier substrate Car is separated from the Waf receptor substrate Rec, laissant la couche mince TL liée au substrat récepteur WafRec.

[0074] It is known that titanium nitride can be used as a separating layer in a laser delamination process using a laser with a wavelength in the infrared range (approximately 2000 nm for TiN), and that single-crystal silicon is transparent to infrared light. A favorable combination is to use a single-crystal wafer and a titanium nitride layer as a Waf carrier substrate. Car and TiN separation layer Car, respectivement. Dans ce cas, le nitrure de titane TiN se décompose en diazote gazeux et en Ti liquide, détachant l'une de l'autre les deux couches qui l'entourent.

[0075] However, materials other than titanium nitride can be used to form the separation layer, provided they significantly absorb the light from the Irr irradiation of step 302, to which the carrier substrate is transparent. It is considered preferable to perform the irradiation of step 302 through the Waf carrier substrate. Car in order to avoid or limit irradiation of the TL thin film, as illustrated by this embodiment. However, it remains possible to proceed differently, and in particular by irradiating the TiN separation layer Car through the Waf receptor substrate Rec , so that the carrier substrate is not necessarily transparent to Irr irradiation and the separation layer does not necessarily have to be absorbing at a wavelength at which the carrier substrate is transparent.

[0076] La(C2) illustrates the result of the separation of the Waf carrier substrate Carof the Waf receptor substrate Recà l'étape 302 : des parties irrégulières de la couche de séparation TiNCarpeuvent subsister, et il est généralement préférable d'éliminer les couches OxDon, Ox2Car, les restes de TiNCaret les couches optionnelles favorisant le collage entre la couche mince TL et le substrat récepteur WafRecafin d'accéder à la couche mince TL.

[0077] In step 304, following step 302, a cleaning step is performed on the thin film TL to remove any remaining layers, for example by CMP (Chemical Mechanical Polishing) and / or wet etching. Figure (C3) illustrates the Waf receiving substrate. Rec after step 304.

[0078] The Waf carrier substrate Car Separated from the thin TL film, the dielectric TiN layer can be recycled for reuse. Carempêche avantageusement les éléments de la couche de séparation de contaminer les couches Ox1Caret le substrat porteur WafCar, ce qui contribue à simplifier le traitement en vue du recyclage et à réduire le coût global du processus. En d'autres termes, la formation de la couche TiNCarpermet de recycler facilement le substrat porteur WafCar. En outre, il est possible de graver sélectivement la couche diélectrique TiNCaret de conserver la couche d'oxyde Ox1Car, de manière à réutiliser le substrat porteur WafCardirectement à l'étape 14 de la méthode PR1, comme illustré à la.

[0079] In the PR2 process, the Waf receptor substrate Rec may include completed or partially formed devices on its upper surface Top Rec, à mettre en contact avec une couche mince TL. Dans une telle situation, un alignement parfait entre lesdits dispositifs et les caractéristiques de la couche mince TL est nécessaire. Le substrat SUB, dont la structure empêche ou limite le gauchissement, facilite avantageusement l'alignement des dispositifs et de la couche mince.

[0080] The figures in this document are not necessarily to scale. Some features and components may be shown in an exaggerated manner relative to other components or in a somewhat schematic form, and some details of conventional elements may not be shown for the sake of clarity and conciseness.

[0081] Of course, the invention is not limited to the embodiment described and other embodiments may be used without departing from the scope of the invention as defined by the claims.

Claims

Substrate (SUB) capable of releasing a thin film under the effect of light irradiation, the substrate comprising: - a carrier substrate (Waf Car ) made of silicon and having a superior surface (Top Car ) and a lower surface (Bot Car ) opposite the upper surface; - an insulating layer (Ox1 Car , SiN Car ) covering each of the upper and lower surfaces; - a separating layer (TiN Car ) formed on the upper surface (Top Car ) of the supporting substrate (Waf Car ); and a layer (TL) to be released onto the upper surface of the carrier substrate (Waf Car ) with the separation layer (TiN Car ) between the layer (TL) to be released and the upper surface of the carrier substrate (Waf Car ). The substrate (SUB) according to claim 1, wherein the insulating layer further covers an edge (Edg) of the carrier substrate (Waf Car ) connecting the upper surface (TopCar ) and the lower surface (Bot Car ) . The substrate (SUB) according to claim 1 or 2, wherein the insulating layer comprises a dielectric layer (SiN Car ) and an internal oxide layer (Ox1 Car ) interposed between the dielectric layer (SiN Car ) and the supporting substrate (Waf Car ) . Substrate (SUB) according to claim 3, wherein the dielectric layer (SiN Car ) is a layer made of silicon nitride. The substrate (SUB) according to claim 3 or 4, in which the internal oxide layer (Ox1 Car ) is made of silicon oxide. The substrate (SUB) according to any one of claims 1 to 5, wherein the separation layer (TiN Car ) is made of titanium nitride. Substrate (SUB) according to any one of claims 1 to 6, wherein a bonding oxide layer (Ox2 Car Ox Don) is interposed between the separation layer (TiN Car ) and the layer to be released (TL). The substrate (SUB) according to claim 7, in which the bonding oxide layer (Ox2 Car Ox Don ) includes a support oxide layer (Ox2 Car ) in direct contact with the separation layer (TiN Car ) and a layer of donor oxide (Ox Don ) in direct contact with the layer (TL) to be released, in which at least one of the supporting oxide layers (Ox2 Car ) and the (TL) layer to be released protrudes from the donor oxide layer (Ox Don ) when viewed in cross-section of the substrate (SUB). The substrate (SUB) according to any one of claims 1 to 8, wherein the layer to be released is formed of a single-crystal material. Substrate (SUB) according to any one of claims 1 to 9, wherein the carrier substrate (Waf Car ) and the separation layer (TiN Car) are respectively transparent and absorbing to light of a given wavelength, so that the layer (TL) to be released can be separated from the carrier substrate (Waf Car ) during irradiation of light of a given wavelength through the carrier substrate. A process (PR1) for manufacturing a substrate (SUB) capable of releasing a thin film under the effect of light irradiation, comprising the following steps: - forming (12, 14) an insulating layer (Ox1 Car , SiN Car ) each covering a top surface (Top Car ) and a smaller surface area (Bot Car ) of a supporting substrate (Waf Car ) made of silicon, the lower surface being opposite the upper surface; - to form (16) a separation layer (TiN Car ) on the upper surface (Top Car ) of the supporting substrate (Waf Car); and- form (20, 22, 24, 30, 32) a layer (TL) to be released onto the upper surface of the carrier substrate (Waf Car ) with the separation layer (TiN Car ) between the layer (TL) to be released and the upper surface of the carrier substrate (Waf Car ). Method (PR1) according to claim 11, wherein the step (12, 14) of forming the insulating layer (Ox1 Car , SiN Car ) covering each of the upper surface (Top Car ) and the lower surface (Bot Car ) of the supporting substrate (Waf Car ) uses a substantially conformal deposition method, preferably a low-pressure chemical vapor deposition. Method (PR1) according to claim 11 or 12, wherein (i) the step of forming (12, 14) the insulating layer (Ox1 Car , SiN Car (ii) and (16) the separation layer formation step (TiN) Car) respectively employ a first deposit method and a second deposit method, the second deposit method being more directive than the first deposit method (Waf Car ). A method (PR1) according to any one of claims 11 to 13, wherein the step (16) of forming the layer to be released (TL) comprises the steps of: - gluing (30) a donor substrate (Waf Don ) on the upper surface of the supporting substrate (Waf Car ) with the separation layer (TiN Car ) interposed between the donor substrate (Waf Don ) and the upper surface of the supporting substrate (Waf Car ); and- remove (32) part of the donor substrate (Waf Don ), another part of the donor substrate remaining on the carrier substrate. Method (PR1) according to claim 14, wherein the step (30) of bonding a donor substrate (Waf Don ) on the upper surface of the supporting substrate (Waf Car) is an oxide-oxide type bonding step.

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