Guided Self-Assembly of Mn Wires on the Si(100)(2 × 1) Surface

Abstract

Doping of group IV semiconductors with Mn is a critical building block in the development of novel spintronics devices, and the fabrication of magnetic nanostructures is the next challenge in this field. The growth of monatomic Mn wires on Si(100)(2 × 1) at room temperature is investigated with scanning tunneling microscopy (STM) and described with a kinetic Monte Carlo (kMC) simulation. Mn forms monatomic wires on the Si(100)(2 × 1) surface, which are always oriented perpendicular to the Si dimer rows, and the Mn wire growth competes with the formation of nanoclusters. The wire quality and wire length distributions are controlled by the vacancy concentration of predominantly C-type defects on the Si surface and the Mn coverage. The phase space covered in this study includes vacancy concentration of 1–18% and coverages of 0.1–0.8 monolayer (ML), at which point the growth of the second layer becomes dominant. A surface phase diagram is established, and the highest wire quality can be achieved for vacancy c...