IMPROVEMENT OF GATE OXIDE RELIABILITY FOR TANTALUM-GATE MOS DEVICES USING XENON PLASMA SPUTTERING TECHNOLOGY

The effects of ion species in sputtering deposition process on gate ox ide reliability have been experimentally investigated. The use of xeno n (Xe) plasma instead of argon (Ar) plasma in tantalum (Ta) film sputt ering deposition for gate electrode formation makes it possible to imp rove the gate oxide reliability. The,Ye plasma process exhibits 1.5 ti mes higher breakdown field and five times higher 50 %-charge-to-breakd own (Q(BD)) In the Ta sputtering deposition process on gate oxide, the physical bombardment of energetic inert-gas ion causes to generate ho le trap sites in gate oxide, resulting in the lower gate oxide reliabi lity. The simplified model providing a better understanding of the emp irical relation between the gate oxide damage and the inert-gas ion bo mbardment energy in gate-Ta sputtering deposition process is also pres ented.