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

Abstract

Anisotropic RuO2 and Ru etching technology for gigabit dynamic random access memory has been developed using high density O2+10% Cl2 plasma in an inductively coupled plasma etching system. Under the conditions of low pressure, high gas flow rate, and large overetching times, we have demonstrated 0.2 μm wide patterns in 0.3-μm-thick RuO2/Ru films and 0.1 μm wide patterns in 0.45-μm-thick Ru films, both with an almost perpendicular taper angle of 89°.