SPUTTERING YIELD OF CHROMIUM BY ARGON AND XENON IONS WITH ENERGIES FROM 50 TO 500-E V

A radioactive tracer technique is described for the quantitative measurement of the sputtering yield of a target material electroplated on a copper substrate. Sputtering yields of chromium by argon and xenon ions with energies from 50 to 500 eV are reported. The ion beams, having a current density ranging from 0.01 to 0.1 mA/cm2 at an operating pressure of 2 x 10(-5) Torr, were produced by a low-energy ion gun. The sputtered atoms were collected on an aluminum foil surrounding the target. Cr-51 was used as the tracer isotope. The results indicate that the radioactive tracer technique is sensitive enough in measuring the extremely small amount of sputtered material at low ion currents and low ion energies.