Vacuum gate dielectric gate-all-around nanowire for hot carrier injection and bias temperature instability free transistor

A gate-all-around (GAA) field effect transistor with vacuum gate dielectric is presented as a structure free from hot-carrier injection and bias temperature instability. A conventional GAA fabrication process is used along with selective removal of the sacrificial gate oxide as an extra process step. The lowered dielectric constant in vacuum gate dielectric can be compensated by the nature of the nanowire and physical oxide thickness reduction. As the nanowire channel is fully surrounded by empty space, reliability issues relevant to the gate dielectric can be completely cleared.