INTERFEROMETRIC MEASUREMENTS OF THE ENERGY OF SPUTTERED COPPER ATOMS IN A MAGNETRON DISCHARGE

Emission line profiles of sputtered Cu atoms in a cylindrical postcath ode magnetron have been measured using a high-resolution scanning Fabr y-Perot interferometer. The filling gas used was Ne. A deconvolution p rocedure was used to unfold the velocity distributions from the emissi on line profiles, measured in a direction parallel and close to the ca thode surface. The velocity distributions were found to be a combinati on of two components-a broad component associated with high velocity a toms entering the measuring volume directly from the cathode, and a na rrow near-Maxwellian distribution attributed to partly thermalized ato ms re-entering the measuring volume. At high pressures (greater than 1 0 Pa) the near-Maxwellian distribution dominates, corresponding to a t emperature of 650-750 K. At lower pressures the energy associated with the motion parallel to the cathode surface is about 2 eV, and is slig htly larger than the energy calculated using a Monte Carlo simulation.