Bottom electrode structures of Pt/RuO2/Ru for integration of (Ba,Sr)TiO3 thin films on polysilicon

The new electrode structures of Pt/RuO2/Ru on polysilicon were prepared by metallorganic chemical vapor deposition (MOCVD). The barrier layers of RuO2 /Ru deposited by MOCVD showed a stable interface and did not affect the sur face morphology of the platinum bottom electrode even at a high annealing t emperature of 800 degrees C. The barrier layers effectively alleviated the interdiffusion of Pt, O, and Si at annealing temperatures above 700 degrees C in an O-2 ambient. Contacts in the as-deposited state exhibited linear c urrent-voltage characteristics with a specific contact resistance of 5.0 x 10(-5) R cm(2). Contacts subjected to thermal annealing up to 800 degrees C for 1 h in an oxygen ambient showed almost constant contact resistance. Th e (Ba, Sr) TiO3 films deposited by MOCVD at low temperature on Pt/RuO2/Ru/p olysilicon showed attractive electrical properties in high-density memory d evices applications. (C) 1999 The Electrochemical Society. S0013-4651 (99)0 2-086-8. All rights reserved.