A method for manufacturing a semiconductor-on-insulator (SeOI) chip comprises: a) providing a SeOI structure, b) building a plurality of isolated field effect transistors (FET) each comprising: a preliminary gate above a channel region, the FETs from a first group having a first preliminary gate length and the FETs from a second group having a smaller second preliminary gate length, a source region and a drain region, and a source electrode and a drain electrode, c) removing at least the preliminary gates of the FETs from the second group, leaving access to channel regions of the FETs, d) thinning a top layer in channel regions of the FETs from the second group, the top layer in channel regions of the first group of FETs having a different thickness, and e) forming functional gates simultaneously on channel regions of the FETs whose preliminary gates were removed.

The present disclosure relates to a multilayer semiconductor-on-insulator structure, comprising, successively from a rear face toward a front face of the structure: a semiconductor carrier substrate with high electrical resistivity, whose electrical resistivity is between 500 .Math.cm and 30 k.Math.cm, a first electrically insulating layer, an intermediate layer, a second electrically insulating layer, which has a thickness less than that of the first electrically insulating layer, an active semiconductor layer, the multilayer structure comprises: at least one FD-SOI region, in which the intermediate layer is an intermediate first semiconductor layer, at least one RF-SOI region, adjacent to the FD-SOI region, in which the intermediate layer is a third electrically insulating layer, the RF-SOI region comprising at least one radiofrequency component plumb with the third electrically insulating layer.

An integrated circuit includes a source region and a drain region spaced apart and extending into a semiconductor layer. A gate electrode extends between the source and the drain regions, and a dielectric layer is between the gate electrode and the semiconductor layer. The dielectric layer includes a first portion having a first thickness and a second portion having a second greater second thickness and a lateral perimeter surrounding the source region. The lateral perimeter includes a first edge having a first linear segment extending between the source region and the drain region along a first direction and a second edge having a second linear segment extending over the semiconductor layer along a different second direction. A fillet of the second portion connects the first linear segment and the second linear segment of the lateral perimeter. .

Disclosed herein are methods for direct bonding. In some embodiments, the direct bonding method includes microwave annealing a dielectric bonding layer of a first element by exposing the dielectric bonding layer to microwave radiation and then directly bonding the dielectric bonding layer of the first element to a second element without an intervening adhesive. The bonding method also includes depositing the dielectric bonding layer on a semiconductor portion of the first element at a first temperature and microwave annealing the dielectric bonding layer at a second temperature lower than the first temperature.

Described examples include an integrated circuit that includes a trench extending into a semiconductor substrate. A silicon nitride body is located within the trench. A polysilicon electrode extends over the silicon nitride body, and a silicon oxynitride layer is located between the silicon nitride body and the polysilicon electrode.