Deterministic doping via self-limited grafting of phosphorus end-terminated polymers

Phosphorus terminated polystyrene polymers with molar mass ranging from 2 to 25 kg/mol and narrow molar mass distribution were synthesized by Atom Transfer Radical Polymerization (ATRP) followed by phosphorylation reaction. Polymers were grafted onto a native silicon oxide surfaces of a silicon wafers by Rapid Thermal Processing (RTP). The self-limiting nature of the grafting to reaction provides an accurate control of the surface density of P atoms as a function of the molar mass of the polymer grafted. After removing the polymeric part of the grafted layer with by O₂ plasma hashing, the phosphorus diffusion in the silicon substrate was promoted by high temperature thermal treatments.