Ion beam synthesis of Mn/As-based clusters in silicon

The synthesis of materials combining ferromagnetism and semiconducting properties is of great interest for the development of devices for future electronics. In order to form magnetic clusters embedded in crystalline Si, sequential ion implantation of As+ and Mn+ was performed with ion fluences in the order of 1016 at/cm2 per ion species and ion energies of 270 keV (As) and 200 keV (Mn), respectively. Based on investigations with Rutherford backscattering spectrometry (RBS) and ferromagnetic resonance (FMR) measurements, we report on our observations regarding the influence of rapid thermal annealing (RTA) on the structural properties of As and Mn co-implanted Si, the redistribution of the implanted elements and the potential relevance to the appearance of ferromagnetism. On the annealed sample with the best magnetic characteristics, nano-sized Mn- and As-rich clusters have been directly identified by transmission electron microscopy (TEM).