Abstract: The invention relates to a process for fabricating a semiconductor that comprises providing a handle substrate comprising a seed substrate and a weakened sacrificial layer covering the seed substrate; joining the handle substrate with a carrier substrate; optionally treating the carrier substrate; detaching the handle substrate at the sacrificial layer to form the semiconductor structure; and removing any residue of the sacrificial layer present on the seed substrate.

Abstract: A heterostructure that includes, successively, a support substrate of a material having an electrical resistivity of less than 10?3 ohm·cm and a thermal conductivity of greater than 100 W·m?1·K?1, a bonding layer, a first seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, a second seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and an active layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and being present in a thickness of between 3 and 100 micrometers. The materials of the support substrate, the bonding layer and the first seed layer are refractory at a temperature of greater than 750° C., the active layer and second seed layer have a difference in lattice parameter of less than 0.005 ?, the active layer is crack-free, and the heterostructure has a specific contact resistance between the bonding layer and the first seed layer that is less than or equal to 0.1 ohm·cm2.

Abstract: The invention relates to methods for fabricating a semiconductor substrate. In one embodiment, the method includes providing an support that includes a barrier layer thereon for preventing loss by diffusion of elements derived from dissociation of the support at epitaxial growth temperatures; providing a seed layer on the barrier layer, wherein the seed layer facilitates epitaxial growth of a single crystal III-nitride semiconductor layer thereon; epitaxially growing a nitride working layer on the thin seed layer; and removing the support to form the substrate.

Abstract: A method for relaxing a layer of a strained material. The method includes depositing a first low-viscosity layer on a first face of a strained material layer; bonding a first substrate to the first low-viscosity layer to form a first composite structure; subjecting the composite structure to heat treatment sufficient to cause reflow of the first low-viscosity layer so as to at least partly relax the strained material layer; and applying a mechanical pressure to a second face of the strained material layer wherein the second face is opposite to the first face and with the mechanical pressure applied perpendicularly to the strained material layer during at least part of the heat treatment to relax the strained material.

Abstract: A method of forming an epitaxially grown layer, preferably by providing a region of weakness in a support substrate and transferring a nucleation portion to the support substrate by bonding. A remainder portion of the support substrate is detached at the region of weakness and an epitaxial layer is grown on the nucleation portion. The remainder portion is separated or otherwise removed from the support portion.

Abstract: Methods of fabricating semiconductor structures and devices include bonding a seed structure to a substrate using a glass. The seed structure may comprise a crystal of semiconductor material. Thermal treatment of the seed structure bonded to the substrate using the glass may be utilized to control a strain state within the seed structure. The seed structure may be placed in a state of compressive strain at room temperature. The seed structure bonded to the substrate using the glass may be used for growth of semiconductor material, or, in additional methods, a seed structure may be bonded to a first substrate using a glass, thermally treated to control a strain state within the seed structure and a second substrate may be bonded to an opposite side of the seed structure using a non-glassy material.

Abstract: Methods of fabricating semiconductor structures and devices include bonding a seed structure to a substrate using a glass. The seed structure may comprise a crystal of semiconductor material. Thermal treatment of the seed structure bonded to the substrate using the glass may be utilized to control a strain state within the seed structure. The seed structure may be placed in a state of compressive strain at room temperature. The seed structure bonded to the substrate using the glass may be used for growth of semiconductor material, or, in additional methods, a seed structure may be bonded to a first substrate using a glass, thermally treated to control a strain state within the seed structure and a second substrate may be bonded to an opposite side of the seed structure using a non-glassy material.

Abstract: A process for fabricating a composite structure for epitaxy, including at least one crystalline growth seed layer of semiconductor material on a support substrate, with the support substrate and the crystalline growth seed layer each having, on the periphery of their bonding face, a chamfer or an edge rounding zone. The process includes at least one step of wafer bonding the crystalline growth seed layer directly onto the support substrate and at least one step of thinning the crystalline growth seed layer. After thinning, the crystalline growth seed layer has a diameter identical to its initial diameter.

Abstract: The invention relates to methods for fabricating a semiconductor substrate. In one embodiment, the method includes providing an support that includes a barrier layer thereon for preventing loss by diffusion of elements derived from dissociation of the support at epitaxial growth temperatures; providing a seed layer on the barrier layer, wherein the seed layer facilitates epitaxial growth of a single crystal III-nitride semiconductor layer thereon; epitaxially growing a nitride working layer on the thin seed layer; and removing the support to form the substrate.

Abstract: An automatic cutting device is described for cutting an assembly. The assembly includes a material having a weakened zone therein that defines a useful layer and being attached to a source substrate. The cutting device includes a cutting mechanism and a holding and positioning mechanism operatively associated with the cutting mechanism. The holding and positioning mechanism positions the material so that the cutting mechanism detaches the layer from the source substrate along the weakened zone. The cutting device also includes a control mechanism for adjusting at least two different portions of the assembly during detachment of the layer to facilitate a more precise detachment.

Abstract: Methods of fabricating semiconductor structures and devices include bonding a seed structure to a substrate using a glass. The seed structure may comprise a crystal of semiconductor material. Thermal treatment of the seed structure bonded to the substrate using the glass may be utilized to control a strain state within the seed structure. The seed structure may be placed in a state of compressive strain at room temperature. The seed structure bonded to the substrate using the glass may be used for growth of semiconductor material, or, in additional methods, a seed structure may be bonded to a first substrate using a glass, thermally treated to control a strain state within the seed structure and a second substrate may be bonded to an opposite side of the seed structure using a non-glassy material.

Abstract: The invention relates to methods for fabricating a semiconductor substrate. In one embodiment, the method includes providing an support that includes a barrier layer thereon for preventing loss by diffusion of elements derived from dissociation of the support at epitaxial growth temperatures; providing a seed layer on the barrier layer, wherein the seed layer facilitates epitaxial growth of a single crystal III-nitride semiconductor layer thereon; epitaxially growing a nitride working layer on the thin seed layer; and removing the support to form the substrate.

Abstract: Methods for transferring of a useful layer from a support are described. In an embodiment, the method includes for facilitating transfer of a useful layer from a support by providing an interface in a first support to define a useful layer; and forming a peripheral recess on the first support below the interface so that the periphery of the interface is exposed to facilitate removal and transfer of the useful layer. An epitaxial layer can be formed on the useful layer after forming the recess, with the width and depth of the recess being sufficient to accommodate the volume of residual material resulting from formation of the epitaxial layer without covering the periphery of the interface. Alternatively, an epitaxial layer can be formed on the useful layer after forming the recess, wherein the peripheral recess is configured for receiving sufficient residual material from the epitaxial layer to prevent bonding between the residual material and the useful layer.

Abstract: An automatic cutting device is described for cutting an assembly. The assembly includes a material having a weakened zone therein that defines a useful layer and being attached to a source substrate. The cutting device includes a cutting mechanism and a holding and positioning mechanism operatively associated with the cutting mechanism. The holding and positioning mechanism positions the material so that the cutting mechanism detaches the layer from the source substrate along the weakened zone. The cutting device also includes a control mechanism for adjusting at least two different portions of the assembly during detachment of the layer to facilitate a more precise detachment.

Abstract: The present invention relates to a method for the formation of an at least partially relaxed strained material layer, the method comprising the steps of providing a seed substrate; patterning the seed substrate; growing a strained material layer on the patterned seed substrate; transferring the strained material layer from the patterned seed substrate to an intermediate substrate; and at least partially relaxing the strained material layer by a heat treatment.

Abstract: The present invention provides methods for relaxing a strained-material layer and structures produced by the methods. Briefly, the methods include depositing a first low-viscosity layer that includes a first compliant material on the strained-material layer, depositing a second low-viscosity layer that includes a second compliant material on the strained-material layer to form a first sandwiched structure and subjecting the first sandwiched structure to a heat treatment such that the reflow of the first and the second low-viscosity layers permits the strained-material layer to at least partly relax.

Abstract: A method of fabricating a device by providing an auxiliary substrate having a metal nitride layer disposed thereon where the nitride layer has a nitrogen face and an opposite face and a dislocation density that is less than about 106, with the nitrogen face of the nitride layer facing the auxiliary substrate; depositing at least one epitaxial nitride layer on the exposed opposite face of the nitride layer of the structure; depositing a further metal layer over at least a portion of the epitaxial nitride layer(s); bonding a final substrate on the deposited metal layer; and removing the auxiliary substrate to form the device from the final substrate and deposited layers. Preferably, the device that is formed includes a LED or laser.

Abstract: The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer.

Abstract: The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer.

Abstract: The invention relates to methods for fabricating a semiconductor substrate. In one embodiment, the method includes transferring a seed layer on to a support substrate; and depositing a working layer on the seed layer to form a composite substrate. The seed layer is made of a material that accommodates thermal expansion of the support substrate and of the working layer. In another embodiment, the method includes providing a source substrate with a weakened zone defining a nucleation layer, bonding a support substrate to the source substrate, detaching the nucleation layer and support substrate at the weakened zone by applying laser irradiation stress, depositing a semiconductor material upon the nucleation layer, bonding a target substrate to the deposited layer and removing the support substrate and nucleation layer. The result is a semiconductor substrate that includes the layer of semiconductor material on a support or target substrate.