Double silicon-on-insulator (SOI) metal oxide semiconductor field effect transistor (MOSFET) structures

A method of forming a silicon-on-insulator (SOI) metal oxide field effect transistor (MOSFET) structure comprising:

• providing a structure comprising an elevated device region and a recessed device region that are separated from each other by an isolation region, said elevated device region comprising a first insulator layer located on a substrate, a first semiconductor layer located on the first insulating layer, a second insulator layer located on the first semiconductor layer, and a second semiconductor layer located on the second insulator layer, and said recessed device region comprising said first buried insulator and said first semiconductor layer;
• forming semiconductor devices in said elevated device region and said recessed device region, wherein the semiconductor device in the elevated device region is formed on the second semiconductor layer and the device in the recessed device region is formed on the first semiconductor layer;
• forming merged source/drain regions in said elevated device region that lay on the first semiconductor layer;
• and
• forming junctions in the elevated and recessed device regions, said junction in the recessed device region extends from an upper surface of the second semiconductor layer down to the first buried insulator layer.