Advanced Dielectrics Deposited by LPCVD

Abstract

AbstractTa2O5 and Nb2O5 films were deposited using the Lam Research Integrity™ reactor. The chemical precursors used were pentaethoxides of Ta and Nb. Typical films were deposited at a rate of 4 nm/min with uniformities of <1.5% lσ in the presence of O2 at 470°C. Annealing the Ta2O5 films did not change the O/Ta ratio. Annealing the Nb2O5 films increased the O/Nb ratio to 2.5/1 at 850°C. Interfacial SiO2 grew to 4 nm after annealing at 850°C for both Ta2O5 and Nb2O5. The as-deposited films were amorphous, but became crystalline above 600°C and 700°C for the Nb2O5 and Ta2O5 films respectively. The TEM observations on crystallization is supported by x-ray diffraction data.