Method of making a transitor

A method for manufacturing a transistor on a stack of layers of the semiconductor on insulator type comprising at least one substrate on which an insulating layer and an initial semiconductor layer are successively disposed, wherein it comprises:

• the formation of at least one oxide pad extending from a top face of the insulating layer, the formation of at least one oxide pad comprising the following steps:
• the formation of at least one cavity in the initial semiconductor layer by etching;
• the formation of a layer of oxide on the surface of said stack of layers of the semiconductor on insulator type, produced so that, in the bottom of the cavities, the film of oxide formed extends at least as far as the insulating layer;
• a partial removal of the film of oxide so as to bare the initial semiconductor layer outside the cavity and to keep at least part of the film of oxide in the cavity in order to leave in place the oxide pad extending from the insulating layer;
• the formation of an additional layer made from semiconductor material covering the oxide pad and intended to form a channel for the transistor;
• the formation of a gate stack above the oxide pad;
• the formation of a source and drain on either side of the gate stack.