AVS 52nd International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI+EM-WeA

Paper MI+EM-WeA5
Nanostructure of Ferromagnetic Mn-implanted Si

Wednesday, November 2, 2005, 3:20 pm, Room 204

Session: Magnetic Semiconductors
Presenter: C. Awo-Affouda, University at Albany-SUNY
Authors: C. Awo-Affouda, University at Albany-SUNY
M. Bolduc, University at Albany-SUNY
K.A. Dunn, University at Albany-SUNY
M.B. Huang, University at Albany-SUNY
F. Ramos, University at Albany-SUNY
G. Agnello, University at Albany-SUNY
B.L. Thiel, University at Albany-SUNY
V.P. LaBella, University at Albany-SUNY
Correspondent: Click to Email
Semiconductor devices which exploit the spin of the electron hold great potential to produce devices with increased functionalities. Making conventional semiconductors ferromagnetic via ion implantation of Mn will aid in fabricating future spintronic devices. We recently demonstrated that ferromagnetism can be achieved via Mn-ion implantation of n-type and p-type Si wafers. A Curie temperature greater than 400K was observed for the p-type samples. The structure of the implanted material was investigated in order to identify the source of the ferromagnetism. SIMS depth profiling of the as-implanted samples showed a typical Gaussian shape profile of Mn atoms in the silicon lattice, which peaks at 250 nm. Post-implant annealing was performed to heal the damage from the implantation process and resulted in a strong redistribution of the Mn atoms. Furthermore diffraction contrast TEM of the annealed samples revealed nanometer size precipitates distributed throughout the implanted region, along with a large band of dislocation and stacking faults. Selected area diffraction patterns gave strong evidence that these phases are MnSi@sub1.7@ crystallites. We will discuss the role of these precipitates on the observed ferromagnetism.