Soi field effect transistor with a back gate for modulating a floating body

A semiconductor structure located in a semiconductor-on-insulator (SOI) substrate and comprising a first field effect transistor and a second field effect transistor therein, wherein said SOI substrate comprises a handle substrate and a buried insulator portion having at least one hole and located directly on said handle substrate, wherein said first transistor comprises:

• a first source region, a first drain region, and a first body region that are located in a first top semiconductor portion abutting said buried insulator portion;
• a dielectric layer abutting said first body, one of said first source region and said first drain region, said first buried insulator portion, and said handle substrate;
• a back gate electrode abutted and surrounded by said dielectric layer;
• and
• a conductive contact via abutting said back gate electrode,
• and wherein said second transistor comprises a second source region, a second drain region, and a second body region that vertically abut said buried insulator portion and are located in a second top semiconductor portion, wherein said second top semiconductor portion is disjoined from said first top semiconductor portion and from said dielectric layer.

A method of forming a semiconductor structure comprising:

• forming a damaged insulator portion by implanting ions into a portion of a buried insulator layer;
• removing said shallow trench isolation structure portion and said damaged insulator portion to form a cavity underneath a top semiconductor portion;
• forming a dielectric layer on a bottom surface of said top semiconductor portion;
• filling said cavity with a conductive material and forming a back gate electrode abutted and surrounded by said dielectric layer;
• and
• forming a body region, a source region, and a drain region a field effect transistor within said top semiconductor portion, wherein said body region and one of said source region and said drain region overlies said back gate electrode.