Fabrication of Si:P delta-doped layers with varying doping densities

We are developing a programme to fabricate atomic scale device structures of phosphorus atoms in a silicon substrate. The first step in this process is the fabrication of 2D Si:P delta-doped layers in silicon, which have recently also been theoretically studied in terms of electrical transport by Hwang and Das Sarma (E. H. Hwang and S. Das Sarma, \textit{Phys. Rev. B}, \textbf{87}, 125411). The Si:P delta-doped layers are expected to exhibit interesting behaviors when the density of the P atom doping is varied through the metal-insulator transition, as well as for the high ($\sim$ 10$^{14}$ per cm$^{2})$ and low (below 10$^{13})$ doping regimes. We are fabricating Si:P delta-doped layers of varying densities from around 6 x 10$^{12}$ to 2 x 10$^{14}$ P atoms per cm$^{2}$, which we will use to experimentally assess the theoretical findings of Hwang and Das Sarma. Details of the fabrication process will also be discussed.