Radio-frequency microelectronic component and manufacturing method, comprises an inductive element placed on an insulator zone traversing the substrate and an insulated feedthrough

The component comprises a semiconductor substrate (1), an inductive element (2) placed on an insulator zone (4) traversing the substrate, and an electric connection feedthrough (5) face of the substrate is greater than the dimensions of the inductive element (2) in order to avoid inductive losses in conductor or semiconductor material. The insulator zone (4) and the insulator ring zone (6) can be implemented at the same steps of the manufacturing method. The semiconductor substrate (1) is of silicon, and the substrate comprises at least one doped zone forming an active element. The feedthrough (5) allows an interconnection between the front face and the rear face of the substrate, and an insulator layer (8) on the rear face of the substrate. The insulator layers (7,8) insulate electrically the substrate from the contact terminals (9) of the feedthrough (5). The insulator layer (7) also insulates electrically the substrate from a resistor (10) and a capacitor (11). The component comprises at least one electric connection between the substrate and an electric ground, and at least one electric connection between the substrate and an element placed on the substrate. A method (claimed) comprises the steps of making cavities in the substrate of depth lesser than the thickness of the substrate, the metallization of cavities for the feedthroughs, filling of cavities with a dielectric material, and removing the substrate thickness from the rear face sufficient to uncover the dielectric material in the cavities. Le composant microélectronique radiofréquence comporte un substrat semiconducteur (1) et un élément inductif (2), disposé sur une zone isolante (4). La zone isolante (4) traverse le substrat de la face avant à la face arrière. La surface de la zone isolante (4), sur la face avant, est supérieure aux dimensions de l'élément inductif associé (2) pour éviter des pertes inductives dans des zones en matériau conducteur ou semiconducteur. Le composant peut aussi comporter une connexion conductrice traversante (5), isolée du substrat par une zone isolante sensiblement annulaire (6). Il est possible de réaliser les zones isolantes traversantes (4) destinées aux éléments inductifs (2) avec les mêmes étapes de fabrication que les zones isolantes (6) des connexions conductrices traversantes (5).