Soitec

Djamel Belhachemi

Oleg Kononchuk

Thierry Barge

Isabelle Huyet

Charlotte Drazek

Raphaël Caulmilone

A method is used to prepare the remainder of a donor substrate, from which a layer has been removed by delamination in a plane weakened by ion implantation. The remainder comprises, on a main face, an annular step corresponding to a non-removed part of the donor substrate. The method comprises the deposition of a smoothing oxide on the main face of the remainder in order to fill the inner space defined by the annular step and to cover at least part of the annular step, as well as heat treatment for densification of the smoothing oxide. A substrate is produced by the method, and the substrate may be used in subsequent processes.

Method for preparing the remainder of a donor substrate, substrate produced by said method, and use of such a substrate

A process for fabricating a substrate for a radiofrequency device includes providing a piezoelectric substrate and a carrier substrate, depositing a dielectric layer on a surface of the piezoelectric substrate, assembling together the piezoelectric substrate and the carrier substrate with a polymerizable adhesive directly between the dielectric layer and the carrier substrate to form an assembled substrate, and polymerizing the polymerizable adhesive layer to form a polymerized layer bonding the piezoelectric substrate to the carrier substrate, the polymerized layer and the dielectric layer together forming an electrically insulating layer between the piezoelectric substrate and the carrier substrate.

Method for manufacturing a substrate for a radiofrequency device

A method for transferring a piezoelectric layer onto a support substrate comprises: —providing a donor substrate including a heterostructure comprising a piezoelectric substrate bonded to a handling substrate, and a polymerized adhesive layer at the interface between the piezoelectric substrate and the handling substrate, —forming a weakened zone in the piezoelectric substrate, so as to delimit the piezoelectric layer to be transferred, —providing the support substrate, —forming a dielectric layer on a main face of the support substrate and/or of the piezoelectric substrate, —bonding the donor substrate to the support substrate, the dielectric layer being at the bonding interface, and—fracturing and separating the donor substrate along the weakened zone at a temperature below or equal to 300° C.

Method for transferring a piezoelectric layer onto a support substrate

A method for manufacturing a substrate for a radiofrequency filter by joining a piezoelectric layer to a carrier substrate via an electrically insulating layer, wherein the method comprises depositing the electrically insulating layer by spin coating an oxide belonging to the family of SOGs (spin-on glasses) on the surface of the piezoelectric layer to be joined to the carrier substrate, followed by an anneal for densifying the electrically insulating layer before joining the piezoelectric layer to the carrier substrate via the electrically insulating layer.

Method for manufacturing a substrate for a radiofrequency filter

A process for fabricating a substrate for a radiofrequency device by joining a piezoelectric layer to a carrier substrate by way of an electrically insulating layer, the piezoelectric layer having a rough surface at its interface with the electrically insulating layer, the process being characterized in that it comprises the following steps: —providing a piezoelectric substrate having a rough surface for reflecting a radiofrequency wave, —depositing a dielectric layer on the rough surface of the piezoelectric substrate, —providing a carrier substrate, —depositing a photo-polymerizable adhesive layer on the carrier substrate, —bonding the piezoelectric substrate to the carrier substrate by way of the dielectric layer and of the adhesive layer, in order to form an assembled substrate, —irradiating the assembled substrate with a light flux in order to polymerize the adhesive layer, the adhesive layer and the dielectric layer together forming the electrically insulating layer.

A layer transfer process comprises depositing a first, temporary bonding layer of SOG comprising methylsiloxane by spin coating on a surface comprising substantially no silicon of an initial substrate, and applying a first heat treatment for densifying the first, temporary bonding layer. An intermediate substrate is joined to the initial substrate, and then thinned A second bonding layer of SOG comprising silicate or methylsilsesquioxane is deposited by spin coating on a surface of the thinned initial substrate and/or a final substrate, and a second heat treatment is applied for densifying the second bonding layer. The thinned initial substrate and the final substrate and then joined, and the intermediate substrate is detached thereafter. The process may be carried out at temperatures below 300&#xb0; C. to avoid damaging components that may be present in the substrates.

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Saint Martin d'Heres, France

Djamel Belhachemi