Je. Foster et al., ANTENNA SPUTTERING IN AN INTERNAL INDUCTIVELY-COUPLED PLASMA FOR IONIZED PHYSICAL VAPOR-DEPOSITION, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 16(2), 1998, pp. 532-535
Ionized physical vapor deposition (IPVD) is an emerging technology for
coating high aspect ratio vias and trenches for the microelectronics
industry. Ionized physical vapor deposition systems typically utilize
an inductive discharge generated by an internal antenna. Because the a
ntenna is immersed in the plasma, the possibility of antenna material
sputtering into the discharge is a contamination issue. In this invest
igation, optical emission spectroscopy is used to acquire spectra from
an IPVD system to monitor the presence of antenna metal in the discha
rge. The observed presence of antenna material in the spectra confirms
that antenna sputtering is occurring. Experimental sputter rates as d
etermined from witness plate observations are in reasonable agreement
with predictions of a simplified model of antenna sputtering, indicati
ng that the sputtering results from large self-bias voltages on the rf
antenna. (C) 1998 American Vacuum Society. [S0734-211X(98)00802-6].