A multilayer composite structure and a method of preparing a multilayer composite structure are provided. The multilayer composite structure comprises a semiconductor handle substrate having a minimum bulk region resistivity of at least about 500 ohm-cm and an isolation region that impedes the transfer of charge carriers along the surface of the handle substrate and reduces parasitic coupling between RF devices.

A method comprises depositing a mask layer on a front-side surface of a wafer, wherein a portion of the wafer has a first resistivity; with the mask layer in place, performing an ion implantation process on a backside surface of the wafer to implant a resistivity reduction impurity into the wafer through the backside surface of the wafer to lower the first resistivity of the portion of the wafer to a second resistivity; after performing the ion implantation process, removing the mask layer from the front-side surface of the wafer; and forming semiconductor devices on the front-side surface of the wafer.

The present disclosure relates to a process for the manufacture of a high resistivity semiconductor substrate, comprising the following stages: providing a first substrate with an in-depth weakened layer; providing a second substrate with a layer of an oxide at the surface; attaching the first substrate to the second substrate so as to form a compound substrate comprising a layer of buried oxide; and cleaving the compound substrate at the level of the weakened layer. The process additionally comprises at least one stage of stabilization, in particular, a stabilization heat treatment, of the second substrate with the layer of oxide before the stage of cleaving at the level of the weakened layer.

In accordance with the present techniques, there is provided a JFET device structures and methods for fabricating the same. Specifically, there is provided a transistor including a semiconductor substrate having a source and a drain. The transistor also includes a doped channel formed in the semiconductor substrate between the source and the drain, the channel configured to pass current between the source and the drain. Additionally, the transistor has a gate comprising a semiconductor material formed over the channel and dielectric spacers on each side of the gate. The source and the drain are spatially separated from the gate so that the gate is not over the drain and source.

A method of manufacturing a substrate for a front-facing image sensor, comprises:—providing a donor substrate comprising a semiconductor layer to be transferred,—providing a semiconductor carrier substrate,—bonding the donor substrate to the carrier substrate, an electrically insulating layer being at the bonding interface,—transferring the semiconductor layer to the carrier substrate,—implanting gaseous ions in the carrier substrate via the transferred semiconductor layer and the electrically insulating layer, and—after the implantation, epitaxially growing an additional semiconductor layer on the transferred semiconductor layer.

In some embodiments, the present disclosure relates to a high-resistivity silicon-on-insulator (SOI) substrate, including a first polysilicon layer arranged over a semiconductor substrate. A second polysilicon layer is arranged over the first polysilicon layer, and a third polysilicon layer is arranged over the second polysilicon layer. An active semiconductor layer over an insulator layer may be arranged over the third polysilicon layer. The second polysilicon layer has an elevated concentration of oxygen compared to the first and third polysilicon layers.

A structure for radiofrequency applications includes: a semiconducting supporting substrate, and a trapping layer arranged on the supporting substrate. The trapping layer includes a higher defect density than a predetermined defect density. The predetermined defect density is the defect density beyond which the electric resistivity of the trapping layer is no lower 10,000 ohm.Math.cm over a temperature range extending from −20° C. to 120° C.

A structure for radiofrequency applications includes: a support substrate of high-resistivity silicon comprising a lower part and an upper part having undergone a p-type doping to a depth D; mesoporous trapping layer of silicon formed in the doped upper part of the support substrate. The depth D is less than 1 micron and the trapping layer has a porosity rate of between 20% and 60%.

A representative method of manufacturing a silicon-on-insulator (SOI) substrate includes steps of depositing an etch stop layer on a dummy wafer, growing an epitaxial silicon layer on the etch stop layer, forming a gettering layer on the epitaxial silicon layer, bonding a buried oxide layer of a main wafer to the gettering layer, and removing the dummy wafer and etch stop layer to expose the epitaxial silicon layer. The SOI substrate has an epitaxial silicon layer adjoining the gettering layer, with the gettering layer interposed between the buried oxide layer and the epitaxial silicon layer.

A method of healing defects generated in a semiconducting layer by implantation of species made in a substrate to form therein an embrittlement plane separating a solid part of the substrate from the semiconducting layer, the semiconducting layer having a front face through which the implanted species pass. The method comprises local annealing of the substrate causing heating of the semiconducting layer, the intensity of which decreases from the front face towards the embrittlement plane. The local annealing may comprise a laser irradiation of a front surface of the substrate.