SIMS depth profile study using metal cluster complex ion bombardment

摘要

SIMS depth profiles using a metal cluster complex ion of Ir_4(CO)_7~+ were studied. An unusual increase of the sputtering yield under the condition of small incident angle may be attributed to the suppression of taking oxygen from flooding O_2 by the formation of a carbon cover-layer derived from Ir_4(CO)_7~+ ion. Even though the roughness of the sputtered surface is small, the depth resolution was not improved by decreasing the cluster ion energy to less than 5 keV, because the carbon cover-layer prevents the formation of surface oxide that buffers atomic mixing. To overcome this issue, it will be necessary to eliminate carbon from the cluster ion.