Integration of high dielectric (Ba1-xSrx)TiO3 thin films into new barrier layer electrode structures

(Ba1-xSrx)TiO3 (BST) films were deposited on the new electrode structures o f Pt/RuO2 + Ta/TiSi2/poly-Si/SiO2/Si (PRTS) and Pt/RuO2 + Ta/poly-Si/SiO2/S i (PRS) by metallorganic chemical vapor deposition. The films deposited on PRTS show smoother morphologies than those on PRS. Titanium-silicide (TiSi2 ) buffer layers formed on poly-Si play an important role in decreasing the roughness of each layer as well as contact resistance between RuO2 + Ta and poly-Si. The electrode structures showed a stable morphology after deposit ion of BST films and annealing at 750 degrees C. The 80 nm thick BST films deposited on PRTS showed a dielec tric constant of 240 and dissipation fact or of 0.01 at 100 kHz. The BST films deposited on PRTS have a leakage curre nt density of about 4.0 X 10(-7) A/cm(2) at 190 kV/cm and breakdown strengt h of 290 kV/cm. (C) 1999 The Electrochemical Society. S0013-4651(98)12-061- X. All rights reserved.