Substrate for radiofrequency applications and associated manufacturing method
AssigneeSoitec
InventorsFrederic Allibert, Christelle Veytizou, Damien Radisson
Life of this patent
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Abstract
A substrate for radiofrequency microelectronic devices comprises a carrier substrate made of a semi-conductor, a sintered composite layer disposed on the carrier substrate and formed from powders of at least a first dielectric material and a second dielectric different from the first material, the sintered composite layer having a thickness larger than 5 microns and a thermal expansion coefficient that is matched with that of the carrier substrate to plus or minus 30%.
Claims17
A substrate including at least one radiofrequency microelectronic device, comprising:
- a carrier substrate consisting essentially of silicon;
- and
- a sintered composite layer placed on the carrier substrate and formed from powders of at least a first dielectric and a second dielectric different from the first, the sintered composite layer having a thickness larger than 5 microns, a thermal expansion coefficient that is matched with that of the carrier substrate to plus or minus 30%, the sintered composite layer including particles of the first dielectric, particles of the second dielectric, and interstices between the particles of the first dielectric and the particles of the second dielectric, a volume fraction of the interstices in the sintered composite layer being between 0% and 50%;
- an intermediate layer on the sintered composite layer on a side thereof opposite the carrier substrate;
- and
- a useful layer directly, molecularly bonded to the intermediate layer, at least a portion of the useful layer forming at least a portion of a radiofrequency microelectronic device.
A method for fabricating a substrate including a radiofrequency microelectronic device, comprising the following steps:
- providing a carrier substrate consisting essentially of silicon, having a first side;
- depositing a layer formed from a mixture of powders of at least a first dielectric and a second dielectric different from the first dielectric, on the first side of the carrier substrate;
- and
- sintering the layer formed from the mixture of powders in order to obtain a sintered composite layer attached to the first side of the carrier substrate and having a thickness larger than 5 microns, the sintered composite layer including particles of the first dielectric, particles of the second dielectric, and interstices between the particles of the first dielectric and the particles of the second dielectric, a volume fraction of the interstices in the sintered composite layer being between 0% and 50%;
- the first dielectric, the second dielectric and a proportion of the first and second dielectrics in the mixture of powders being chosen to give the sintered composite layer a thermal expansion coefficient that is matched with that of the carrier substrate to plus or minus 30%;
- depositing an intermediate layer on the sintered composite layer on a side thereof opposite the carrier substrate;
- and
- directly bonding, by molecular adhesion, a useful layer to the intermediate layer such that the intermediate layer and the sintered composite layer are disposed between the useful layer and the carrier substrate, at least a portion of the useful layer forming at least a portion of a radiofrequency microelectronic device.
Dependencies are inferred from the claim text.