ANGULAR-DISTRIBUTION OF THE SPUTTERED ATOMS FROM TBFECO TARGETS

The angular distribution of the sputtered Th, Fe, and Co atoms from th e elemental targets could be described by cos(n) theta distribution wi th n = 1.90, 0.54, and 1.01 for Th, Fe, and Co, respectively. For TbFe Co composite targets with mixed elemental and intermetallic compound p hases, the overall angular distribution of the sputtered Tb, Fe, and C o atoms from the mixed phases could also be described by the cos(n) th eta distribution function, and the values of the n's were related to t he volume percentage of the intermetallic compound content in the comp osite target. This was not true of the Th distribution for a target co ntaining high intermetallic compound content. In that sample, an off-n ormal term has to be added to the cos(n) theta distribution function. It was found that a composite target with about 23 vol % intermetallic compound would produce a uniform composition distribution of TbFeCo f ilm on the substrate.