Process for manufacturing a semiconductor material wafer having power regions dielectrically insulated from circuitry regions

摘要

A manufacturing process is carried out starting from an SOI type wafer including a top silicon layer and a bottom silicon layer separated from each other by a buried silicon dioxide layer. In the top layer, a LOCOS type sacrificial region is formed and then removed, so as to form a cavity that extends in depth as far as the buried oxide layer. Subsequently, the cavity is filled with epitaxial or polycrystalline silicon, so as to form a power region extending between the top surface and the bottom surface of the wafer; then lateral insulation regions are formed that insulate the power region from the circuitry region.