Anisotropic etching of RuO2 and Ru with high aspect ratio for gigabit dynamic random access memory

Anisotropic RuO2 and Ru etching technology for gigabit dynamic random acces s memory has been developed using high density O-2+10% Cl-2 plasma in an in ductively coupled plasma etching system. Under the conditions of low pressu re, high gas flow rate, and large overetching times, we have demonstrated 0 .2 mu m wide patterns in 0.3-mu m-thick RuO2/Ru films and 0.1 mu m wide pat terns in 0.45-mu m-thick Ru films, both with an almost perpendicular taper angle of 89 degrees. (C) 2000 American Vacuum Society. [S0734-211X(00)01604 -8].