Electrostatic doping and related devices

Electrostatic doping is a unique privilege of ultrathin-body devices. In a conventional thick-body MOS capacitor the positive gate voltage induces a 2D inversion layer at the surface, separated from the neutral substrate by a depletion region. In a fully depleted film, not only is the neutral region absent but also the minority carriers escape 2D confinement. Thanks to volume inversion, they spread from the top interface down to the film–BOX interface. The ultrathin body is filled with electrons and looks like being N-type doped. The reciprocal P-type electrostatic doping is formed by volume accumulation for VG<0. The possibility to emulate P–N junctions, out of nothing, in a fully depleted body represents a paradigm shift in the design of reconfigurable components with enriched functionality.