DIELECTRIC ETCHING FOR 0.18 MU-M TECHNOLOGIES

Two types of plasma source, high density plasma and magnetically enhan ced reactive ion etching, have been compared on contact and vias etch process performances for 0.25 mu m complementary metal-oxide semicondu ctor technology application. High density plasma is able to provide hi gh oxide etch rate, low contact resistance and high yield on 350 nm co ntact size after etching. On the other hand, selectivity to photoresis t is low and nonuniform across the wafer. Moreover, due to interaction between high density plasma and deep ultraviolet photoresist, striati ons are transferred on contact walls. Magnetically enhanced reactive i on etching is able to provide uniform etch rate and high selectivity t o photoresist. Low contact resistance and high yield have also been ob tained on 300 nm contact size after etching. The main disadvantage of this plasma source is the low oxide etch rate. Antenna effects due to contact opening have been evaluated on test structures. The results sh ow a minimized induced damage effect for the high density plasma type reactor. (C) 1998 American Vacuum Society.