A damage immune field effect transistor with a vacuum gate dielectric is presented. The device consists of a suspended silicon nanowire and an independently controlled double-gate. The vacuum gate dielectric with a thickness of 20 nm is formed by a sacrificial layer deposition and removal process. The vacuum gate dielectric is found to be resistant to radiation-induced damage. Furthermore, it shows a very high tolerance against hot-carrier stress. The excellent stability in the radiative environment and high electric field is attributed to the absence of material in the vacuum gate dielectric. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3520618]