Anomalous Hall effect in Mn-implanted p-type Si
|Wei Ji Huang , Hung-Ta Lin , Shuo-Hong Wang , Tsung-Shune Chin|
Department of Materials Science and Engineering, National Tsing Hua University (NTHU), 101, Sec 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
Si1-xMnx alloy has been regarded as the most compatible material of DMSs to semiconductor industry of today. The Curie temperature (TC) reported so far is around 75 K, even higher than room temperature. Si1-xMnx samples were fabricated by implanting Mn+ ions into p-type silicon (100) substrates with an energy of 150 keV at the doses of (5~10) x1015/cm2 to produce average volume concentrations of 1~3 at% in the top 200 nm of Si substrates. In order to activate the Mn ion into Si lattice site and remove the damages caused during ion implantation process, post annealing were carried out at temperatures ranging from 700 to 900oC for 30 sec under Ar atmosphere. In particular, B+ ions were first implanted at energy of 25 keV, the corresponding projected range calculated by TRIM simulation program shows B+ atoms was located at interior side than Mn+ atoms. Due to conductivity enhancement by co-doping B atoms, the current can be confined and accurately flows into the Si1-xMnx layer while the magnetotransport measurement The field dependence of the Hall resistance (RHall) in Si1-xMnx sample were performed by Van der Pauw method at temperatures ranging from 10 K to room temperature. Strong anomalous Hall effect clearly reveal that the present sample is ferromagnetic for temperature below 30 K. Moreover, we have observed the specific variation in magnetic and electrical behaviors while the Si1-xMnx samples were under different post annealing condition. The further magnetic characterization and detailed microstructure were also performed by SQUID magnetometer and TEM analysis, respectively. The local composition distribution of Si1-xMnx was precisely characterized by an energy dispersive x-ray spectrometer. The implication of the effect of the additional B+ implantation and the corresponding magnetotransport properties will also be discussed.
Presentation: Poster at E-MRS Fall Meeting 2006, Symposium E, by Wei Ji Huang
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-15 07:39 Revised: 2009-06-07 00:44