PURPOSE: To prevent the mixing of unnecessary element into target thus to prevent the deterioration of the characteristic of element, by providing a slit made of silicon having an opening of predetermined area for determining the ion injection area into the target.
CONSTITUTION: The target 1 is a rotatable polygonal rod mountable with many sheets of specimens where a slit 4 constructed of silicon single crystal board having an opening 4' for determining the ion injection area and a slit for suppressing the secondary electron are located between the target 1 and the ion source. Said slit 4 is maintained to the ground potential to block a portion of ion beam from the ion source and to irradiate only such ion as passed through said opening 4' on the target 1 while has no blocking function on such ion beam as passed through the opening 4'. Consequently the mixing of unnecessary element into the target can be prevented.
SAKURAI TERUO
OKAMURA SHIGERU
