A semiconductor device includes a first source/drain region a second source/drain region, and a gate region interposed between the first and second source/drain regions. At least one nanowire has a first end anchored to the first source/drain region and an opposing second end anchored to the second source/drain region such that the nanowire is suspended above the wafer in the gate region. At least one gate electrode is in the gate region. The gate electrode contacts an entire surface of the nanowire to define a gate-all-around configuration. At least one pair of oxidized spacers surrounds the at least one gate electrode to electrically isolate the at least one gate electrode from the first and second source/drain regions.