Heavily doped and extremely shallow junctions on insulator by SONCTION (SilicON Cut-off juncTION) process

The proposed SONCTION (SilicON Cut-off juncTION) process consists in tailoring of the junction depth by physical removing of a "sacrificial" bottom part of the junction. This becomes possible since the junction is implanted within a bilayer of SiGe capped with silicon. It enables a selective removal of the SiGe layer from underneath the Silicon, thus physically reducing the junction depth. The cavity left out by the removed SiGe is refilled with oxide, thus preventing the smearing out of the junction profile which therefore can be doped to a high level and comfortably annealed. As the SiGe and Si layers are fabricated by epitaxy, feasibility and perfect reproducibility of thin junctions, such as a few nm, is ensured.