Measurement of sputtering rate for 10 keV O2+ ions with ion microanalyzer

The sputtering rates of single-crystal Si and polycrystalline Ag, Cu, Ni and Al were measured. The target materials were bombarded with oxygen ions accelerated at 10 kV. The sputtering rates of the target materials were a fifth of those obtained with an argon ion beam. The difference was larger than the difference between the masses of the oxygen and argon ions used for the incident beams. However, the sputtering rates with oxygen ions were related to the strength of the bonds between the atoms of the target material by the following expression, from analogy with an argon ion beam. S sub(r) = 4(I/D)(E sub(c)/M sub(t))sup(-1.4), where S sub(r) is the sputtering rate, I is the current density of the incident ions, and D, M sub(t) and E sub(c) are the atomic density, mass number and cohesive energy of the target material, respectively. (author)