Process for fabrication, by means of epitaxial recrystallization, of insulated-gate field-effect transistors with junctions of minimum depth

A process for producing an insulated gate field effect transistor on a first region of a monocrystalline silicon substrate of a first type of conductivity, comprising the steps of:

• forming a first insulating layer on a second region of the substrate contained within the first region thereof;
• forming a conducting layer on the first insulating layer and then forming a second insulating layer on the conducting layer, the first insulating layer and the conducting layer respectively forming a gate dielectric and a gate electrode of the field effect transistor;
• forming insulating walls on at least uncovered portions of edges of the conducting layer;
• forming a polycrystalline silicon layer overlaying at least the first region and implanting the polycrystalline silicon layer with impurities for causing it to have a second type of conductivity which is opposite to the first type of conductivity, wherein the atomic species of such impurities, the concentration thereof and the implantation energy are selected so as to inject the impurities into the substrate where the substrate is in direct contact with the polycrystalline silicon layer and so as to cause the conversion of polycrystalline silicon to amorphous silicon;
• and including a low temperature heat treatment step for causing an epitaxial rerystallization into monocrystalline silicon of at least parts of the polycrystalline silicon layer which have been previously converted into amorphous silicon, the recrystallized monocrystalline silicon parts forming drain and source regions of the field effect transistor.