Fabrication method of a transistor with improved field effect

A fabrication method of a field-effect transistor, comprising the following consecutive steps:

• providing a substrate comprising:
• a film made from first semiconductor material,
• a gate dielectric covered by a gate electrode,
• source and drain areas separated by the gate electrode,
• a protection layer covering the gate electrode and the source and drain areas,
• an access hole to the source area and/or to the drain areas,
• depositing a metallic material in the access hole of the source and/or drain areas so that the metallic material is in contact with the first semiconductor material,
• depositing an electrically conducting barrier layer, said barrier layer being non-reactive with the first semiconductor material and non-reactive with the metallic material,
• depositing an electric conductor on said barrier layer so as to fill said access hole,
• performing a heat treatment so that the metallic material react with the semiconductor material to form an alloy between a metallic material and the semiconductor material generating a set of stresses on a conduction channel arranged between the source and drain areas.