Sg. Woo et al., Etching characteristics of fine Ta patterns with electron cyclotron resonance chlorine plasma, JPN J A P 1, 39(12B), 2000, pp. 6996-6999
In this research, the etching characteristics of a Ta thin film with chlori
ne plasma was studied using an electron cyclotron resonance plasma etching
system. The native Ta oxide on the surface was removed by a sputtering mech
anism, and then ion-assisted Ta etching, desorption of Ta chloride assisted
by ion bombardment, proceeded. The atomic chlorine, which is believed to b
e the most active species responsible for etching, could be used as an indi
cator of the Ta etching process. By double step etching, an accelerated for
mation of Ta chloride by a chemical-reaction-dominant process in the second
step, following the sputtering-dominant process step, successfully protect
ed side walls, resulting in the suppression of the microloading effect.