LARGE MAGNETORESISTANCE OF SPUTTERED BI THIN FILMS AND APPLICATION OF SPIN DEVICE

  • M. H. Jeun (Korea Institute of science and Technology, Department of Electronic Materials Engineering, Kwangwoon University) ;
  • Lee, K. I. (Korea Institute of science and Technology) ;
  • Kim, D. Y. (Korea Institute of science and Technology) ;
  • J. Y. Chang (Korea Institute of science and Technology) ;
  • K. H. Shin (Korea Institute of science and Technology) ;
  • S. H. Han (Korea Institute of science and Technology) ;
  • J. G. Ha (Department of Electronic Materials Engineering, Kwangwoon University) ;
  • Lee, W. Y. (Department of Materials Science and Engineering, Yonsei University)
  • Published : 2003.06.01

Abstract

Bismuth (Bi) has been an attractive materials for studying spin dependent transport properties because it shows very large magnetoresistance (MR) resulting from its highly anisotropic Fermi surface, low carrier concentrations, long carrier mean free path 1 and small effective carrier mass m*[1-3]. With all the intriguing properties, difficulty in fabrication of high quality Bi thin films may have prevented extensive application of Bi in magnetic field sensing and spin-injection devices. Previous works found that the surface roughness and small grain size in 100-200 nm of Bi thin film made by evaporation and sputtering are major causes of low MR. Although relatively higher MR in electrodeposited Bi followed by annealing was reported, it still suffers from rough sulfate roughness which is so severs that it is hardly able to make a field sensing and spin-injection device using conventional photolithography process.

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