This paper describes the formation of ultrathin tantalum oxide capacit
ors, using rapid thermal nitridation (RTN) of the storage-node polycry
stalline-silicon surface prior to low-pressure chemical vapor depositi
on of tantalum oxide, using penta-ethoxy-tantalum [(Ta(OC2H5)5] and ox
ygen gas mixture. The films are annealed at 600-900-degrees-C in dry O
2 atmosphere. Densification of the as-deposited film by annealing in d
ry O2 is indispensable to the formation of highly reliable ultra-thin
tantalum oxide capacitors. The RTN treatment reduces the SiO2 equivale
nt thickness and leakage current of the tantalum oxide film, and impro
ves the time dependent dielectric breakdown characteristics of the fil
m.