A comprehensive study on the physicochemical and electrical properties of Si doped with the molecular doping method

Semiconductor doping through solution-based self- 17 assembling provides a simple, scalable, and cost-effective 18 alternative to standard methods and additionally allows 19 conformality on structured surfaces. Among the several 20 solution-based deposition techniques, dip coating is the most 21 promising. It consists in immersing the target to be doped 22 inside a solution containing the dopant precursor. During this 23 process, the molecule bonds to the target surface with a self- 24 limiting process ruled by its steric properties. Successive 25 annealing leads to layer decomposition and diffusion of 26 dopant atoms inside the substrate. Most of the work on 27 molecular doping lacks information on the molecule/Si 28 interface chemical properties, on the mechanisms of the 29 molecule evolution during the coating, and of its decom- 30 position after the diffusion step. Moreover, it has so far been 31 devoted to the molecules design to tune the final dopant dose 32 and distribution. Here, the main results on the molecular 33 doping are reviewed, and new findings on the interface 34 characteristics, also in terms of mono- and multilayers 35 formation are presented. A systematic study, carried out by 36 fixing the dopant precursor and varying the coating 37 conditions, is also reported, demonstrating that the important 38 doping features can be controlled precisely and that 39 uniformity can be achieved at nanometer level.