POLYCIDE GATE ETCHING USING A HELICAL RESONATOR ON AN APPLIED MATERIALS PRECISION-5000 PLATFORM

We modified a polycide gate etching chamber of an Applied Materials Pr ecision 5000 platform to accept a commercially available Prototech 150 -mm-diam helical resonator plasma source to extend the utility of this proven manufacturing platform to 0.25 mu m technology and beyond. We successfully demonstrated the use of the helical resonator on the Prec ision 5000 platform to etch WSix/alpha-Si gate stacks using a multiste p process. At low pressures (<10 mTorr), the helical resonator etches polysilicon and WSix more uniformly than a standard Precision 5000 MER IE chamber. In addition, the WSix-to-alpha-Si selectivity for the WSix etching step is also higher with the high-density source. (C) 1997 Am erican Vacuum Society.