Effect of ultraclean sputtering process on Cr segregation in CoCrTa thin film media

The microstructure of Cr segregation in CoCrTa media fabricated under the ultra clean sputtering process was examined by using transmission electron microscopy and electron energy loss spectroscopy. As a result, by applying the UC process: (1) A clear Cr segregated grain boundary is formed from the interface between the Cr underlayer to the top surface of the magnetic layer, leading to the reduction of intergranular exchange coupling. (2) The diffusion of the Cr atom from inner to outer grain is enhanced, resulting in the inducement of high H-k(grain). (3) The oxygen content is reduced to less than about 10(19) atoms/cm(3), which is 2 or 3 orders of magnitude lower than that in n-CoCrTa. (C) 1999 Elsevier Science B.V. All rights reserved.