Pre-annealing effects on al metallization properties in high density FeRAM device

Abstract

Metallization properties of TiN/Al/Ti (metal-1) layers deposited by sputtering method were evaluated in a new 16 Mb FeRAM device. The two main features of the device were double W bit-line and Pt/(Bi,La)(4)Ti3O12/Pt ferroelectric capacitor. The metal-1 films were deposited on both the Pt top electrode and the W bit-line after fabricating the contact holes. The contact filling behaviors of the metal-1 layers were mainly depended on the pre-annealing condition performed before depositing the metal-1 layers. The optimized pre-annealing conditions was 400 degrees C/N-2/30 min on W bit-line. From the result, a 16 Mb FeRAM device was successfully developed.