SPUTTER PROCESS DIAGNOSTICS BY NEGATIVE-IONS

We measured the energy distributions of negative ions during reactive sputtering of silicon in oxygen. Various oxygen containing negative io ns are formed in the cathode sheath or directly at the sputter target, respectively. These negative ions are accelerated away from the catho de by the electrical field, and can be detected using a mass spectrome ter facing the sputter magnetron. The origin of each ion can be determ ined from peak structures in the energy distribution. Additionally the flux of different negative ions provides information on poisoning of the target by oxide films. (C) 1998 American Institute of Physics.